PIN a 4 cifre: migrazione 017, login-pin, pin-users, PUT pin, capoturno via PIN (#59)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docker-compose.dev.yml

@@ -14,6 +14,7 @@ services:
       --authentication-policy=mysql_native_password
       --character-set-server=utf8mb4
       --collation-server=utf8mb4_unicode_ci
+      --default-time-zone=+00:00
     healthcheck:
       test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
       interval: 10s

docker-compose.yml

@@ -14,6 +14,7 @@ services:
       --authentication-policy=mysql_native_password
       --character-set-server=utf8mb4
       --collation-server=utf8mb4_unicode_ci
+      --default-time-zone=+00:00
     healthcheck:
       test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
       interval: 10s

src/backend/api/middleware/api_key.py

@@ -1,10 +1,18 @@
 """API Key authentication dependency for FastAPI."""
+from datetime import timedelta
+
 from fastapi import Depends, HTTPException, Request, status
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from src.backend.database import get_db
+from src.backend.config import settings
+from src.backend.models.orm.api_key import ApiKey
 from src.backend.models.orm.user import User
+from src.backend.services.auth_service import hash_api_key
+from src.backend.utils.tempo import utcnow
+
+_RENEW_INTERVAL = timedelta(minutes=5)
 
 
 async def get_current_user(
@@ -24,15 +32,25 @@ async def get_current_user(
         )
 
     result = await db.execute(
-        select(User).where(User.api_key == api_key, User.active == True)
+        select(ApiKey, User)
+        .join(User, User.id == ApiKey.user_id)
+        .where(ApiKey.key_hash == hash_api_key(api_key), User.active == True)
     )
-    user = result.scalar_one_or_none()
+    row = result.first()
+    now = utcnow()
 
-    if user is None:
+    if row is None or row[0].expires_at <= now:
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
-            detail="Invalid or inactive API key",
+            detail="Invalid or expired API key",
         )
+    key_row, user = row
+
+    # Sliding TTL, written at most once per _RENEW_INTERVAL to spare the DB.
+    if key_row.last_used_at is None or now - key_row.last_used_at > _RENEW_INTERVAL:
+        key_row.last_used_at = now
+        key_row.expires_at = now + timedelta(hours=settings.api_key_ttl_hours)
+        await db.flush()
 
     # Store user_id in request state for access logging middleware
     request.state.user_id = user.id

src/backend/api/routers/auth.py

@@ -1,5 +1,6 @@
 """Authentication router - login, logout, profile."""
-from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi import APIRouter, Depends, HTTPException, Request, status
+from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from src.backend.database import get_db
@@ -8,10 +9,17 @@ from src.backend.models.orm.user import User
 from src.backend.models.api.user import (
     LoginRequest,
     LoginResponse,
+    PinLoginRequest,
+    PinUserItem,
     UserProfileUpdate,
     UserResponse,
 )
-from src.backend.services.auth_service import authenticate_user, login_user, logout_user
+from src.backend.services.auth_service import (
+    authenticate_pin,
+    authenticate_user,
+    login_user,
+    logout_user,
+)
 
 router = APIRouter(prefix="/api/auth", tags=["auth"])
 
@@ -32,17 +40,47 @@ async def login(data: LoginRequest, db: AsyncSession = Depends(get_db)):
     )
 
 
+@router.get("/pin-users", response_model=list[PinUserItem])
+async def pin_users(db: AsyncSession = Depends(get_db)):
+    """Utenti che possono entrare con PIN (#59): attivi, non admin, con PIN.
+
+    Pubblico per costruzione (serve prima del login): espone solo id e nome.
+    """
+    result = await db.execute(
+        select(User).where(
+            User.active == True,  # noqa: E712
+            User.is_admin == False,  # noqa: E712
+            User.pin_hash.is_not(None),
+        )
+    )
+    items = [
+        PinUserItem(id=u.id, display_name=u.display_name or u.username)
+        for u in result.scalars().all()
+    ]
+    items.sort(key=lambda i: i.display_name.casefold())
+    return items
+
+
+@router.post("/login-pin", response_model=LoginResponse)
+async def login_pin(data: PinLoginRequest, db: AsyncSession = Depends(get_db)):
+    """Login con user_id e PIN a 4 cifre (#59); stessa risposta del login."""
+    user = await authenticate_pin(db, data.user_id, data.pin)
+    api_key = await login_user(db, user)
+    return LoginResponse(user=UserResponse.model_validate(user), api_key=api_key)
+
+
 @router.post("/logout", status_code=status.HTTP_204_NO_CONTENT)
 async def logout(
+    request: Request,
     all_sessions: bool = False,
     user: User = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
-    """Logout. The API key is shared across stations logged in as the same
-    user, so by default this does not invalidate it - only this station's
-    session (its Flask session, on the client side) ends. Pass
-    ?all_sessions=true to invalidate the key everywhere."""
-    await logout_user(db, user, all_sessions=all_sessions)
+    """Logout. Deletes this session's API key only; ?all_sessions=true
+    deletes every key of the user."""
+    await logout_user(
+        db, user, key=request.headers.get("X-API-Key"), all_sessions=all_sessions
+    )
 
 
 @router.get("/me", response_model=UserResponse)

src/backend/api/routers/measurements.py

@@ -2,6 +2,8 @@
 import csv
 import io
 from datetime import datetime
+from src.backend.models.api.tipi import UtcNaiveInput
+from src.backend.utils.tempo import as_utc_naive, iso_utc, to_local, utcnow
 
 from fastapi import APIRouter, Depends, HTTPException, Query, status
 from fastapi.responses import StreamingResponse
@@ -19,6 +21,7 @@ from src.backend.models.orm.recipe import RecipeVersion
 from src.backend.models.orm.setting import SystemSetting
 from src.backend.models.orm.user import User
 from src.backend.models.api.measurement import (
+    CurrentCycleResponse,
     MeasurementAuthorisation,
     MeasurementBatchCreate,
     MeasurementCreate,
@@ -97,6 +100,24 @@ async def get_task_progress(
     return TaskProgressListResponse(tasks=tasks)
 
 
+@router.get("/current-cycle", response_model=CurrentCycleResponse)
+async def get_current_cycle(
+    production_run_id: int = Query(..., gt=0),
+    task_id: int = Query(..., gt=0),
+    user: User = Depends(require_measurement_tec),
+    db: AsyncSession = Depends(get_db),
+):
+    """Quotes of this task already measured in the cycle under way.
+
+    Asked on load, so that a reload mid-cycle does not present quotes again that
+    were taken a moment ago.
+    """
+    rows = await measurement_service.current_cycle_measurements(
+        db, production_run_id, task_id,
+    )
+    return CurrentCycleResponse(measurements=rows)
+
+
 @router.post("/{measurement_id}/authorise", response_model=MeasurementResponse)
 async def authorise_measurement(
     measurement_id: int,
@@ -126,6 +147,7 @@ async def authorise_measurement(
 
     supervisor = await auth_service.authorise_supervisor(
         db, action.supervisor_username, action.supervisor_password,
+        user_id=action.supervisor_user_id, pin=action.supervisor_pin,  # #59
     )
     measurement = await measurement_service.authorise_measurement(
         db, measurement, supervisor,
@@ -213,8 +235,8 @@ async def get_measurements(
     measured_by: int | None = Query(None),
     lot_number: str | None = Query(None),
     serial_number: str | None = Query(None),
-    date_from: datetime | None = Query(None),
-    date_to: datetime | None = Query(None),
+    date_from: UtcNaiveInput = Query(None),
+    date_to: UtcNaiveInput = Query(None),
     pass_fail: str | None = Query(None, pattern="^(pass|warning|fail)$"),
     production_run_id: int | None = Query(None, gt=0),
     page: int = Query(1, ge=1),
@@ -271,8 +293,8 @@ async def export_measurements_csv(
     measured_by: int | None = Query(None),
     lot_number: str | None = Query(None),
     serial_number: str | None = Query(None),
-    date_from: datetime | None = Query(None),
-    date_to: datetime | None = Query(None),
+    date_from: UtcNaiveInput = Query(None),
+    date_to: UtcNaiveInput = Query(None),
     pass_fail: str | None = Query(None, pattern="^(pass|warning|fail)$"),
     user: User = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
@@ -353,7 +375,7 @@ async def export_measurements_csv(
             neutralise_csv_cell(m.lot_number or ""),
             neutralise_csv_cell(m.serial_number or ""),
             m.input_method,
-            m.measured_at.isoformat(),
+            iso_utc(m.measured_at),
             m.synced_to_csv,
         ])
 
@@ -363,6 +385,6 @@ async def export_measurements_csv(
         iter([output.getvalue()]),
         media_type="text/csv",
         headers={
-            "Content-Disposition": f"attachment; filename=measurements_{datetime.now().strftime('%Y%m%d_%H%M%S')}.csv"
+            "Content-Disposition": f"attachment; filename=measurements_{to_local(utcnow()).strftime('%Y%m%d_%H%M%S')}.csv"
         },
     )

src/backend/api/routers/production.py

@@ -141,6 +141,7 @@ async def pause_production_run(
     run = await production_service.get_run(db, run_id)
     supervisor = await auth_service.authorise_supervisor(
         db, action.supervisor_username, action.supervisor_password,
+        user_id=action.supervisor_user_id, pin=action.supervisor_pin,  # #59
     )
     run = await production_service.pause_run(db, run, user, supervisor, note=action.note)
     return await _as_response(db, run)
@@ -157,6 +158,7 @@ async def resume_production_run(
     run = await production_service.get_run(db, run_id)
     supervisor = await auth_service.authorise_supervisor(
         db, action.supervisor_username, action.supervisor_password,
+        user_id=action.supervisor_user_id, pin=action.supervisor_pin,  # #59
     )
     run = await production_service.resume_run(db, run, user, supervisor, note=action.note)
     return await _as_response(db, run)
@@ -173,6 +175,7 @@ async def close_production_run(
     run = await production_service.get_run(db, run_id)
     supervisor = await auth_service.authorise_supervisor(
         db, action.supervisor_username, action.supervisor_password,
+        user_id=action.supervisor_user_id, pin=action.supervisor_pin,  # #59
     )
     run = await production_service.close_run(db, run, user, supervisor, note=action.note)
     return await _as_response(db, run)

src/backend/api/routers/reports.py

@@ -1,5 +1,5 @@
 """Reports router — PDF report generation endpoints for Metrologist."""
-from datetime import datetime
+from src.backend.models.api.tipi import UtcNaiveInput
 
 from fastapi import APIRouter, Depends, HTTPException, Query, status
 from fastapi.responses import Response
@@ -18,8 +18,8 @@ async def download_spc_report(
     recipe_id: int = Query(...),
     subtask_id: int = Query(...),
     version_id: int | None = Query(None),
-    date_from: datetime | None = Query(None),
-    date_to: datetime | None = Query(None),
+    date_from: UtcNaiveInput = Query(None),
+    date_to: UtcNaiveInput = Query(None),
     operator_id: int | None = Query(None),
     lot_number: str | None = Query(None),
     serial_number: str | None = Query(None),
@@ -52,8 +52,8 @@ async def download_measurement_report(
     recipe_id: int = Query(...),
     subtask_id: int | None = Query(None),
     version_id: int | None = Query(None),
-    date_from: datetime | None = Query(None),
-    date_to: datetime | None = Query(None),
+    date_from: UtcNaiveInput = Query(None),
+    date_to: UtcNaiveInput = Query(None),
     operator_id: int | None = Query(None),
     lot_number: str | None = Query(None),
     serial_number: str | None = Query(None),

src/backend/api/routers/setup.py

@@ -5,8 +5,8 @@ NOT protected by API Key auth (standalone access).
 """
 import hmac
 import random
-import secrets
 from datetime import datetime, timedelta
+from src.backend.utils.tempo import iso_utc, utcnow
 from pathlib import Path
 
 from alembic import command
@@ -25,7 +25,7 @@ from src.backend.models.orm import (
     User, Recipe, RecipeVersion, RecipeTask, RecipeSubtask, Measurement,
 )
 from src.backend.models.orm.station import Station, StationRecipeAssignment
-from src.backend.services.auth_service import hash_password
+from src.backend.services.auth_service import hash_password, issue_api_key, revoke_all_keys
 from src.backend.services.measurement_service import calculate_pass_fail
 
 router = APIRouter(prefix="/api/setup", tags=["setup"])
@@ -321,8 +321,6 @@ async def create_admin(body: CreateAdminBody):
     """Create an admin user with all roles."""
     _check_password(body.password)
 
-    api_key = secrets.token_hex(32)
-
     async with async_session_factory() as session:
         async with session.begin():
             user = User(
@@ -332,9 +330,10 @@ async def create_admin(body: CreateAdminBody):
                 display_name=body.admin_display_name,
                 roles=["Maker", "MeasurementTec", "Metrologist"],
                 is_admin=True,
-                api_key=api_key,
             )
             session.add(user)
+            await session.flush()
+            api_key = await issue_api_key(session, user)
 
     return {
         "status": "ok",
@@ -404,7 +403,6 @@ async def seed_demo_data(body: PasswordBody):
                     email=u["email"],
                     roles=u["roles"],
                     is_admin=u["is_admin"],
-                    api_key=secrets.token_hex(32),
                 )
                 session.add(user)
                 created_users.append(user)
@@ -558,7 +556,7 @@ async def seed_demo_data(body: PasswordBody):
             tec_user = created_users[2]  # tec1
             lot_numbers = ["LOT-2025-001", "LOT-2025-002", "LOT-2025-003", "LOT-2025-004"]
             serial_numbers = [f"SN-{i:04d}" for i in range(1, 13)]
-            base_date = datetime.now()
+            base_date = utcnow()
 
             all_subtasks = subtasks_1 + subtasks_2
             measurements_created = 0
@@ -606,8 +604,8 @@ async def list_users(body: PasswordBody):
                     "roles": u.roles or [],
                     "is_admin": u.is_admin,
                     "active": u.active,
-                    "created_at": u.created_at.isoformat() if u.created_at else None,
-                    "last_login": u.last_login.isoformat() if u.last_login else None,
+                    "created_at": iso_utc(u.created_at) or None,
+                    "last_login": iso_utc(u.last_login) or None,
                 }
                 for u in users
             ],
@@ -652,7 +650,6 @@ async def manage_user(body: ManageUserBody):
                     email=body.email,
                     roles=body.roles,
                     is_admin=body.is_admin,
-                    api_key=secrets.token_hex(32),
                 )
                 session.add(user)
                 await session.flush()
@@ -707,7 +704,7 @@ async def change_user_password(body: ChangeUserPasswordBody):
                     detail=f"User ID {body.user_id} not found",
                 )
             user.password_hash = hash_password(body.new_password)
-            user.api_key = None  # Invalidate sessions
+            await revoke_all_keys(session, user.id)  # Invalidate sessions
 
     return {"status": "ok", "message": f"Password changed for '{user.username}'"}
 
@@ -730,7 +727,7 @@ async def toggle_user_active(body: ToggleUserActiveBody):
                 )
             user.active = not user.active
             if not user.active:
-                user.api_key = None  # Invalidate sessions on deactivation
+                await revoke_all_keys(session, user.id)  # on deactivation
             new_status = "active" if user.active else "inactive"
 
     return {"status": "ok", "message": f"User '{user.username}' is now {new_status}", "active": user.active}

src/backend/api/routers/statistics.py

@@ -1,5 +1,6 @@
 """Statistics router - SPC endpoints for Metrologist dashboard."""
 from datetime import datetime
+from src.backend.models.api.tipi import UtcNaiveInput
 
 from fastapi import APIRouter, Depends, HTTPException, Query, status
 from sqlalchemy import and_, select
@@ -100,8 +101,8 @@ async def get_summary(
     recipe_id: int = Query(...),
     version_id: int | None = Query(None),
     subtask_id: int | None = Query(None),
-    date_from: datetime | None = Query(None),
-    date_to: datetime | None = Query(None),
+    date_from: UtcNaiveInput = Query(None),
+    date_to: UtcNaiveInput = Query(None),
     operator_id: int | None = Query(None),
     lot_number: str | None = Query(None),
     serial_number: str | None = Query(None),
@@ -122,8 +123,8 @@ async def get_capability(
     recipe_id: int = Query(...),
     subtask_id: int = Query(...),
     version_id: int | None = Query(None),
-    date_from: datetime | None = Query(None),
-    date_to: datetime | None = Query(None),
+    date_from: UtcNaiveInput = Query(None),
+    date_to: UtcNaiveInput = Query(None),
     operator_id: int | None = Query(None),
     lot_number: str | None = Query(None),
     serial_number: str | None = Query(None),
@@ -145,8 +146,8 @@ async def get_control_chart(
     recipe_id: int = Query(...),
     subtask_id: int = Query(...),
     version_id: int | None = Query(None),
-    date_from: datetime | None = Query(None),
-    date_to: datetime | None = Query(None),
+    date_from: UtcNaiveInput = Query(None),
+    date_to: UtcNaiveInput = Query(None),
     operator_id: int | None = Query(None),
     lot_number: str | None = Query(None),
     serial_number: str | None = Query(None),
@@ -172,8 +173,8 @@ async def get_histogram(
     recipe_id: int = Query(...),
     subtask_id: int = Query(...),
     version_id: int | None = Query(None),
-    date_from: datetime | None = Query(None),
-    date_to: datetime | None = Query(None),
+    date_from: UtcNaiveInput = Query(None),
+    date_to: UtcNaiveInput = Query(None),
     operator_id: int | None = Query(None),
     lot_number: str | None = Query(None),
     serial_number: str | None = Query(None),

src/backend/api/routers/users.py

@@ -6,8 +6,14 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from src.backend.database import get_db
 from src.backend.api.middleware.api_key import require_admin_user
 from src.backend.models.orm.user import User
-from src.backend.models.api.user import UserCreate, UserPasswordChange, UserResponse, UserUpdate
-from src.backend.services.auth_service import create_user, hash_password, regenerate_api_key
+from src.backend.models.api.user import PinSet, UserCreate, UserPasswordChange, UserResponse, UserUpdate
+from src.backend.services.auth_service import (
+    create_user,
+    hash_password,
+    regenerate_api_key,
+    revoke_all_keys,
+    set_user_pin,
+)
 
 router = APIRouter(prefix="/api/users", tags=["users"])
 
@@ -146,11 +152,35 @@ async def change_user_password(
     if user is None:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
     user.password_hash = hash_password(data.password)
-    user.api_key = None
+    await revoke_all_keys(db, user.id)
     await db.flush()
     return {"message": f"Password changed for user {user.username}"}
 
 
+@router.put("/{user_id}/pin", status_code=status.HTTP_200_OK)
+async def change_user_pin(
+    user_id: int,
+    data: PinSet,
+    admin: User = Depends(require_admin_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """Imposta o toglie (pin null) il PIN di un utente (admin, #59/#51).
+
+    422 se l'utente e' admin. Il PIN non si restituisce mai.
+    """
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalar_one_or_none()
+    if user is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
+    if user.is_admin:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail="Admin users cannot have a PIN",
+        )
+    await set_user_pin(db, user, data.pin)
+    return {"message": f"PIN {'set' if data.pin else 'removed'} for user {user.username}"}
+
+
 @router.delete("/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
 async def deactivate_user(
     user_id: int,
@@ -168,7 +198,7 @@ async def deactivate_user(
             detail="Cannot deactivate yourself",
         )
     user.active = False
-    user.api_key = None
+    await revoke_all_keys(db, user.id)
     await db.flush()
 
 
@@ -183,5 +213,5 @@ async def regenerate_user_key(
     user = result.scalar_one_or_none()
     if user is None:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
-    new_key = await regenerate_api_key(db, user_id)
+    new_key = await regenerate_api_key(db, user)
     return {"api_key": new_key, "message": f"API key regenerated for user {user.username}"}

src/backend/api/routers/vision.py

@@ -5,19 +5,25 @@ the numbers: that is what lets a station's configuration change without touching
 the frontend or the recipes.
 """
 import io
+import json
 
+from fastapi.responses import FileResponse
 from fastapi import APIRouter, Depends, File, Form, HTTPException, UploadFile, status
 from PIL import Image
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from src.backend.api.middleware.api_key import require_maker, require_measurement_tec
-from src.backend.api.routers.files import ALLOWED_IMAGE_TYPES, validate_file_size
+from src.backend.api.routers.files import (
+    ALLOWED_IMAGE_TYPES, resolve_upload_path, validate_file_size,
+)
 from src.backend.config import settings
 from src.backend.database import get_db
 from src.backend.models.api.vision import (
-    VisionExecuteResponse, VisionMeasurementResult, VisionReferenceImageResponse,
+    VisionExecuteResponse, VisionMeasurementResult, VisionRecipeResponse,
+    VisionRecipeUploadResponse, VisionReferenceImageResponse,
 )
+from src.backend.models.orm.vision import VisionResult
 from src.backend.models.orm.task import RecipeTask
 from src.backend.models.orm.user import User
 from src.backend.services import vision_service
@@ -126,7 +132,7 @@ async def execute(
 ) -> VisionExecuteResponse:
     task = await _task_or_404(db, task_id)
 
-    result, saved = await vision_service.execute_task(
+    result, saved, report = await vision_service.execute_task(
         db,
         task,
         await _read_image(image),
@@ -135,6 +141,7 @@ async def execute(
         lot_number=lot_number,
         serial_number=serial_number,
         production_run_id=production_run_id,
+        image_ext=_IMAGE_EXTENSIONS.get(image.content_type, "png"),
     )
     await db.commit()
 
@@ -147,6 +154,111 @@ async def execute(
             )
             for m in saved
         ],
+        outcome=report.get("outcome"),
+        overlay=report.get("overlay") or [],
+        image_url=f"/api/vision/results/{result.id}/image",
+        failures=report.get("failures") or [],
+    )
+
+
+@router.get("/results/{result_id}/image")
+async def get_result_image(
+    result_id: int,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(require_measurement_tec),
+) -> FileResponse:
+    """The image a vision run measured, as saved by `execute` (#46)."""
+    result = (await db.execute(
+        select(VisionResult).where(VisionResult.id == result_id)
+    )).scalar_one_or_none()
+    if result is None or not result.image_path:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND, detail="Result image not found",
+        )
+    return FileResponse(resolve_upload_path(result.image_path))
+
+
+def _422(errors: list[str]) -> HTTPException:
+    # detail e' una lista di stringhe: il frontend legge i 422 solo da `detail`.
+    return HTTPException(
+        status_code=status.HTTP_422_UNPROCESSABLE_CONTENT, detail=errors,
+    )
+
+
+@router.post("/tasks/{task_id}/recipe", response_model=VisionRecipeUploadResponse)
+async def upload_recipe(
+    task_id: int,
+    recipe: UploadFile = File(...),
+    files: list[UploadFile] = File(default=[]),
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(require_maker),
+) -> VisionRecipeUploadResponse:
+    """Load a VisionSuite v2 recipe plus its meta files onto a task (#46)."""
+    task = await _task_or_404(db, task_id)
+    if task.task_type not in vision_service.VISION_TASK_TYPES:
+        raise _422([f"task type {task.task_type!r} does not run a vision recipe"])
+
+    raw = await recipe.read()
+    if not validate_file_size(len(raw)):
+        raise _422([f"recipe exceeds {settings.max_upload_size_mb}MB"])
+    try:
+        graph = json.loads(raw)
+    except ValueError:
+        raise _422(["the recipe is not valid JSON"])
+    if not isinstance(graph, dict):
+        raise _422(["the recipe must be a JSON object"])
+
+    uploads: list[tuple[str, bytes]] = []
+    for f in files:
+        content = await f.read()
+        if not validate_file_size(len(content)):
+            raise _422([f"file {f.filename!r} exceeds {settings.max_upload_size_mb}MB"])
+        uploads.append((f.filename or "", content))
+    placed, errors = vision_service.match_recipe_files(graph, uploads)
+    if errors:
+        raise _422(errors)
+
+    # The folder is content-addressed and immutable; writing it before the
+    # validation is harmless (an orphan folder is never referenced) and the
+    # worker needs it on disk to validate meta files.
+    try:
+        recipe_dir = vision_service.store_recipe_folder(task.id, graph, placed)
+    except ValueError as exc:
+        raise _422([str(exc)])
+    check = await vision_service.validate_recipe(graph, recipe_dir)
+    if not check["ok"]:
+        raise _422([str(e) for e in check["errors"]] or ["the recipe is not valid"])
+
+    task.vision_json = graph
+    task.vision_recipe_dir = recipe_dir
+    await db.commit()
+    return VisionRecipeUploadResponse(
+        task_id=task.id,
+        recipe_dir=recipe_dir,
+        files=vision_service.list_recipe_files(recipe_dir),
+        outputs=check["outputs"],
+    )
+
+
+@router.get("/tasks/{task_id}/recipe", response_model=VisionRecipeResponse)
+async def get_recipe(
+    task_id: int,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(require_maker),
+) -> VisionRecipeResponse:
+    task = await _task_or_404(db, task_id)
+    outputs: list[dict] = []
+    if task.vision_json:
+        check = await vision_service.validate_recipe(
+            task.vision_json, task.vision_recipe_dir,
+        )
+        outputs = check.get("outputs", [])
+    return VisionRecipeResponse(
+        task_id=task.id,
+        recipe_dir=task.vision_recipe_dir,
+        recipe=task.vision_json,
+        files=vision_service.list_recipe_files(task.vision_recipe_dir),
+        outputs=outputs,
     )
 
 

src/backend/config.py

@@ -28,6 +28,9 @@ class Settings(BaseSettings):
     db_user: str = "tmflow"
     db_password: str = _DEFAULT_DB_PASSWORD
 
+    # Presentation time zone (DB is UTC, #42)
+    display_timezone: str = "Europe/Rome"
+
     # Server
     server_host: str = "0.0.0.0"
     server_port: int = 8000
@@ -38,6 +41,9 @@ class Settings(BaseSettings):
     # configured limits to keep the cluster-wide effective limit close to what
     # was configured instead of multiplying it by N.
     web_concurrency: int = 1
+
+    # API key session lifetime (hours); renewed on use (env API_KEY_TTL_HOURS).
+    api_key_ttl_hours: int = 24
     # How many reverse proxies between the client and this API are trusted to
     # have appended their own hop to X-Forwarded-For (Nginx, in the default
     # deploy). Used by RateLimitMiddleware._client_ip. 0 disables proxy header

src/backend/migrations/versions/015_api_key_hash.py

@@ -0,0 +1,54 @@
+"""API keys as SHA-256 hashes, one per session (#41)
+
+Replaces the plaintext `users.api_key` column with an `api_keys` table: one
+row per login, holding only the SHA-256 hex digest, an expiry and the last
+use. Existing keys are invalidated on purpose, not migrated - the plaintext
+is exactly what must stop existing, so everybody logs in once again.
+
+Revision ID: 015_api_key_hash
+Revises: 014_vision_fk_ondelete
+Create Date: 2026-10-06
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = '015_api_key_hash'
+down_revision: Union[str, None] = '014_vision_fk_ondelete'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        'api_keys',
+        sa.Column('id', sa.Integer(), primary_key=True, autoincrement=True),
+        sa.Column('user_id', sa.Integer(), nullable=False),
+        sa.Column('key_hash', sa.String(64), nullable=False),
+        sa.Column('created_at', sa.DateTime(), nullable=False),
+        sa.Column('expires_at', sa.DateTime(), nullable=False),
+        sa.Column('last_used_at', sa.DateTime(), nullable=True),
+        sa.ForeignKeyConstraint(
+            ['user_id'], ['users.id'], name='fk_api_keys_user_id', ondelete='CASCADE'
+        ),
+    )
+    op.create_index('ix_api_keys_key_hash', 'api_keys', ['key_hash'], unique=True)
+    op.create_index('ix_api_keys_user_id', 'api_keys', ['user_id'])
+
+    with op.batch_alter_table('users') as batch:
+        batch.drop_index('ix_users_api_key')
+        batch.drop_constraint('uq_users_api_key', type_='unique')
+        batch.drop_column('api_key')
+
+
+def downgrade() -> None:
+    with op.batch_alter_table('users') as batch:
+        batch.add_column(sa.Column('api_key', sa.String(64), nullable=True))
+        batch.create_unique_constraint('uq_users_api_key', ['api_key'])
+        batch.create_index('ix_users_api_key', ['api_key'])
+
+    op.drop_index('ix_api_keys_user_id', table_name='api_keys')
+    op.drop_index('ix_api_keys_key_hash', table_name='api_keys')
+    op.drop_table('api_keys')

src/backend/migrations/versions/016_vision_recipe_dir.py

@@ -0,0 +1,30 @@
+"""recipe_tasks.vision_recipe_dir: cartella della ricetta VisionSuite v2 (#46)
+
+Percorso relativo sotto upload_path della cartella immutabile che contiene
+recipe.json e i file di meta (DXF, modelli .npz, ...).
+
+Revision ID: 016_vision_recipe_dir
+Revises: 015_api_key_hash
+Create Date: 2026-10-07
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = '016_vision_recipe_dir'
+down_revision: Union[str, None] = '015_api_key_hash'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # batch: SQLite non sa fare DROP COLUMN nativo su tutte le versioni
+    with op.batch_alter_table('recipe_tasks') as batch:
+        batch.add_column(sa.Column('vision_recipe_dir', sa.String(500), nullable=True))
+
+
+def downgrade() -> None:
+    with op.batch_alter_table('recipe_tasks') as batch:
+        batch.drop_column('vision_recipe_dir')

src/backend/migrations/versions/017_user_pin.py

@@ -0,0 +1,34 @@
+"""users: PIN a 4 cifre per login rapido e capoturno (#59)
+
+pin_hash (bcrypt, mai in chiaro), contatore errori consecutivi e fine blocco.
+
+Revision ID: 017_user_pin
+Revises: 016_vision_recipe_dir
+Create Date: 2026-10-07
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = '017_user_pin'
+down_revision: Union[str, None] = '016_vision_recipe_dir'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # batch: SQLite non sa fare DROP COLUMN nativo su tutte le versioni
+    with op.batch_alter_table('users') as batch:
+        batch.add_column(sa.Column('pin_hash', sa.String(255), nullable=True))
+        batch.add_column(sa.Column(
+            'pin_failed_count', sa.Integer(), nullable=False, server_default='0'))
+        batch.add_column(sa.Column('pin_locked_until', sa.DateTime(), nullable=True))
+
+
+def downgrade() -> None:
+    with op.batch_alter_table('users') as batch:
+        batch.drop_column('pin_locked_until')
+        batch.drop_column('pin_failed_count')
+        batch.drop_column('pin_hash')

src/backend/models/api/measurement.py

@@ -1,8 +1,8 @@
 """Pydantic schemas for Measurement operations."""
-from datetime import datetime
+from src.backend.models.api.tipi import UtcDateTime, UtcNaiveInput
 from typing import Optional
 
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, model_validator
 
 
 class MeasurementCreate(BaseModel):
@@ -54,8 +54,8 @@ class MeasurementResponse(BaseModel):
     # Who let this value stand, when it was out of tolerance. Null on a value in
     # tolerance - and on one that is not and is still waiting for an answer.
     supervisor_id: Optional[int] = None
-    authorised_at: Optional[datetime] = None
-    measured_at: datetime
+    authorised_at: Optional[UtcDateTime] = None
+    measured_at: UtcDateTime
     synced_to_csv: bool
 
 
@@ -71,8 +71,21 @@ class MeasurementListResponse(BaseModel):
 class MeasurementAuthorisation(BaseModel):
     """Credentials of the supervisor allowing an out-of-tolerance value to stand."""
 
-    supervisor_username: str = Field(..., min_length=1)
-    supervisor_password: str = Field(..., min_length=1)
+    # #59: o username+password, oppure supervisor_user_id+supervisor_pin
+    supervisor_username: Optional[str] = Field(None, min_length=1)
+    supervisor_password: Optional[str] = Field(None, min_length=1)
+    supervisor_user_id: Optional[int] = Field(None, gt=0)
+    supervisor_pin: Optional[str] = Field(None, pattern=r"^[0-9]{4}$")
+
+    @model_validator(mode="after")
+    def _one_credential_pair(self):
+        by_password = self.supervisor_username and self.supervisor_password
+        by_pin = self.supervisor_user_id and self.supervisor_pin
+        if not (by_password or by_pin):
+            raise ValueError(
+                "supervisor credentials required: username+password or user_id+pin"
+            )
+        return self
 
 
 class TaskProgressResponse(BaseModel):
@@ -91,6 +104,21 @@ class TaskProgressListResponse(BaseModel):
     tasks: list[TaskProgressResponse]
 
 
+class CycleMeasurementResponse(BaseModel):
+    """One quote already measured in the cycle under way."""
+
+    subtask_id: int
+    value: float
+    pass_fail: str
+    measured_at: UtcDateTime
+
+
+class CurrentCycleResponse(BaseModel):
+    """The quotes to restore on the screen after a reload; empty if the task is closed."""
+
+    measurements: list[CycleMeasurementResponse]
+
+
 class MeasurementQuery(BaseModel):
     """Schema for measurement query filters."""
     recipe_id: Optional[int] = None
@@ -99,8 +127,8 @@ class MeasurementQuery(BaseModel):
     measured_by: Optional[int] = None
     lot_number: Optional[str] = None
     serial_number: Optional[str] = None
-    date_from: Optional[datetime] = None
-    date_to: Optional[datetime] = None
+    date_from: UtcNaiveInput = None
+    date_to: UtcNaiveInput = None
     pass_fail: Optional[str] = Field(None, pattern="^(pass|warning|fail)$")
     page: int = Field(1, ge=1)
     per_page: int = Field(50, ge=1, le=500)

src/backend/models/api/production.py

@@ -1,8 +1,8 @@
 """Pydantic schemas for production runs and their events."""
-from datetime import datetime
+from src.backend.models.api.tipi import UtcDateTime
 from typing import Literal, Optional
 
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, model_validator
 
 
 class ProductionRunCreate(BaseModel):
@@ -21,7 +21,7 @@ class ProductionEventResponse(BaseModel):
     supervisor_id: Optional[int]
     task_id: Optional[int] = None
     note: Optional[str]
-    created_at: datetime
+    created_at: UtcDateTime
 
 
 class ProductionRunResponse(BaseModel):
@@ -36,11 +36,11 @@ class ProductionRunResponse(BaseModel):
     serial_number: Optional[str]
     status: str
     measurement_interval_minutes: Optional[int]
-    next_measurement_at: Optional[datetime]
+    next_measurement_at: Optional[UtcDateTime]
     cycle_count: int
-    started_at: datetime
-    paused_at: Optional[datetime]
-    closed_at: Optional[datetime]
+    started_at: UtcDateTime
+    paused_at: Optional[UtcDateTime]
+    closed_at: Optional[UtcDateTime]
     closed_by: Optional[int]
     statistics_path: Optional[str] = None
 
@@ -49,7 +49,7 @@ class ProductionRunResponse(BaseModel):
     # overdue is a fact the operator must see, not deduce.
     seconds_to_next_measurement: Optional[int] = None
     overdue: bool = False
-    server_time: Optional[datetime] = None
+    server_time: Optional[UtcDateTime] = None
 
     # The measurement tasks of this run's version, in execution order. The client
     # needs them to bring the operator back to the measurement when the interval
@@ -64,8 +64,21 @@ class ProductionRunWithEventsResponse(ProductionRunResponse):
 class SupervisorAction(BaseModel):
     """Credentials of the supervisor authorising a line stop or a close."""
 
-    supervisor_username: str = Field(..., min_length=1)
-    supervisor_password: str = Field(..., min_length=1)
+    # #59: o username+password, oppure supervisor_user_id+supervisor_pin
+    supervisor_username: Optional[str] = Field(None, min_length=1)
+    supervisor_password: Optional[str] = Field(None, min_length=1)
+    supervisor_user_id: Optional[int] = Field(None, gt=0)
+    supervisor_pin: Optional[str] = Field(None, pattern=r"^[0-9]{4}$")
+
+    @model_validator(mode="after")
+    def _one_credential_pair(self):
+        by_password = self.supervisor_username and self.supervisor_password
+        by_pin = self.supervisor_user_id and self.supervisor_pin
+        if not (by_password or by_pin):
+            raise ValueError(
+                "supervisor credentials required: username+password or user_id+pin"
+            )
+        return self
     note: Optional[str] = None
 
 

src/backend/models/api/recipe.py

@@ -1,5 +1,5 @@
 """Pydantic schemas for Recipe and RecipeVersion operations."""
-from datetime import datetime
+from src.backend.models.api.tipi import UtcDateTime
 from typing import Optional, TYPE_CHECKING
 
 from pydantic import BaseModel, ConfigDict, Field
@@ -51,7 +51,7 @@ class RecipeVersionResponse(BaseModel):
     version_number: int
     is_current: bool
     created_by: int
-    created_at: datetime
+    created_at: UtcDateTime
     change_notes: Optional[str] = None
     tasks: list["TaskResponse"] = []
 
@@ -72,7 +72,7 @@ class RecipeResponse(BaseModel):
     requires_serial: bool = False
     allow_manual_input: bool = False
     created_by: int
-    created_at: datetime
+    created_at: UtcDateTime
     active: bool
     current_version: Optional[RecipeVersionResponse] = None
 

src/backend/models/api/station.py

@@ -1,5 +1,5 @@
 """Pydantic schemas for Station and StationRecipeAssignment."""
-from datetime import datetime
+from src.backend.models.api.tipi import UtcDateTime
 from typing import Optional
 
 from pydantic import BaseModel, ConfigDict, Field
@@ -29,7 +29,7 @@ class StationResponse(BaseModel):
     notes: Optional[str]
     active: bool
     created_by: int
-    created_at: datetime
+    created_at: UtcDateTime
 
 
 class StationRecipeAssignmentCreate(BaseModel):
@@ -42,7 +42,7 @@ class StationRecipeAssignmentResponse(BaseModel):
     station_id: int
     recipe_id: int
     assigned_by: int
-    assigned_at: datetime
+    assigned_at: UtcDateTime
 
 
 class RecipeSummary(BaseModel):

src/backend/models/api/statistics.py

@@ -1,5 +1,5 @@
 """Pydantic schemas for SPC statistics responses."""
-from datetime import datetime
+from src.backend.models.api.tipi import UtcDateTime, UtcNaiveInput
 from typing import Optional
 
 from pydantic import BaseModel, Field
@@ -10,8 +10,8 @@ class StatisticsQuery(BaseModel):
     recipe_id: int
     version_id: Optional[int] = None
     subtask_id: Optional[int] = None
-    date_from: Optional[datetime] = None
-    date_to: Optional[datetime] = None
+    date_from: UtcNaiveInput = None
+    date_to: UtcNaiveInput = None
     operator_id: Optional[int] = None
     lot_number: Optional[str] = None
     serial_number: Optional[str] = None
@@ -20,7 +20,7 @@ class StatisticsQuery(BaseModel):
 class ControlChartData(BaseModel):
     """Data for X-bar/R control chart."""
     values: list[float]
-    timestamps: list[datetime]
+    timestamps: list[UtcDateTime]
     mean: float
     ucl: float  # Upper Control Limit
     lcl: float  # Lower Control Limit
@@ -60,7 +60,7 @@ class CapabilityData(BaseModel):
 
 class TrendData(BaseModel):
     """Temporal trend data for capability indices."""
-    dates: list[datetime]
+    dates: list[UtcDateTime]
     cpk_values: list[Optional[float]]
     ppk_values: list[Optional[float]]
     n_per_period: list[int]

src/backend/models/api/tipi.py

@@ -0,0 +1,14 @@
+"""Shared Pydantic types for datetimes (#42): UTC in the DB, explicit +00:00 on the wire."""
+from datetime import datetime
+from typing import Annotated, Optional
+
+from pydantic import AfterValidator, PlainSerializer
+
+from src.backend.utils.tempo import as_utc_naive, to_utc_aware
+
+UtcDateTime = Annotated[
+    datetime, PlainSerializer(lambda v: to_utc_aware(v).isoformat(), return_type=str)
+]
+
+# Input: aware values are converted to UTC naive, naive is taken as UTC.
+UtcNaiveInput = Annotated[Optional[datetime], AfterValidator(as_utc_naive)]

src/backend/models/api/user.py

@@ -1,5 +1,5 @@
 """Pydantic schemas for User operations."""
-from datetime import datetime
+from src.backend.models.api.tipi import UtcDateTime
 from typing import Optional
 
 from pydantic import BaseModel, ConfigDict, Field
@@ -48,8 +48,10 @@ class UserResponse(BaseModel):
     language_pref: str
     theme_pref: str
     active: bool
-    created_at: datetime
-    last_login: Optional[datetime] = None
+    created_at: UtcDateTime
+    last_login: Optional[UtcDateTime] = None
+    # #59: solo il fatto che il PIN esista, mai l'hash
+    has_pin: bool = False
 
 
 class UserPasswordChange(BaseModel):
@@ -68,3 +70,21 @@ class LoginResponse(BaseModel):
     user: UserResponse
     api_key: str
     message: str = "Login successful"
+
+
+class PinUserItem(BaseModel):
+    """Voce dell'elenco pubblico per il login con PIN (#59): solo id e nome."""
+    id: int
+    display_name: str
+
+
+class PinLoginRequest(BaseModel):
+    """Login con PIN (#59)."""
+    user_id: int
+    pin: str = Field(..., pattern=r"^[0-9]{4}$")
+
+
+class PinSet(BaseModel):
+    """Imposta (4 cifre) o toglie (null) il PIN di un utente (#59)."""
+    pin: Optional[str] = Field(None, pattern=r"^[0-9]{4}$")
+

src/backend/models/api/vision.py

@@ -1,5 +1,5 @@
 """Pydantic schemas for the vision execution response."""
-from datetime import datetime
+from src.backend.models.api.tipi import UtcDateTime
 
 from pydantic import BaseModel, ConfigDict
 
@@ -16,6 +16,34 @@ class VisionExecuteResponse(BaseModel):
     vision_result_id: int
     engine_version: str
     measurements: list[VisionMeasurementResult]
+    # Esito VisionSuite (informativo: il verdetto lo danno utl/ltl), overlay
+    # in px immagine, URL dell'immagine salvata e strumenti falliti (#46).
+    outcome: str | None = None
+    overlay: list[dict] = []
+    image_url: str | None = None
+    failures: list[dict] = []
+
+
+class VisionRecipeOutput(BaseModel):
+    """One numeric output a recipe offers to the quotes."""
+    key: str
+    quantity: str | None = None
+    unit: str | None = None
+
+
+class VisionRecipeUploadResponse(BaseModel):
+    task_id: int
+    recipe_dir: str
+    files: list[str]
+    outputs: list[VisionRecipeOutput]
+
+
+class VisionRecipeResponse(BaseModel):
+    task_id: int
+    recipe_dir: str | None = None
+    recipe: dict | None = None
+    files: list[str]
+    outputs: list[VisionRecipeOutput]
 
 
 class VisionReferenceImageResponse(BaseModel):
@@ -28,4 +56,4 @@ class VisionReferenceImageResponse(BaseModel):
     note: str | None = None
     station_id: int | None = None
     device_code: str | None = None
-    acquired_at: datetime
+    acquired_at: UtcDateTime

src/backend/models/orm/__init__.py

@@ -1,5 +1,6 @@
 """SQLAlchemy models for TieMeasureFlow."""
 from src.backend.models.orm.user import User
+from src.backend.models.orm.api_key import ApiKey
 from src.backend.models.orm.recipe import Recipe, RecipeVersion
 from src.backend.models.orm.task import RecipeTask, RecipeSubtask
 from src.backend.models.orm.measurement import Measurement
@@ -11,6 +12,7 @@ from src.backend.models.orm.vision import VisionReferenceImage, VisionResult
 
 __all__ = [
     "User",
+    "ApiKey",
     "Recipe",
     "RecipeVersion",
     "RecipeTask",

src/backend/models/orm/api_key.py

@@ -0,0 +1,25 @@
+"""API key sessions: one row per login, stored as a SHA-256 hash."""
+from datetime import datetime
+from typing import Optional
+
+from sqlalchemy import DateTime, ForeignKey, Integer, String
+from sqlalchemy.orm import Mapped, mapped_column
+
+from src.backend.database import Base
+
+
+class ApiKey(Base):
+    """One API key per login session.
+
+    Only the SHA-256 hex digest is stored, never the key. Dates are naive UTC.
+    """
+    __tablename__ = "api_keys"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    user_id: Mapped[int] = mapped_column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    key_hash: Mapped[str] = mapped_column(String(64), nullable=False, unique=True, index=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
+    expires_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
+    last_used_at: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)

src/backend/models/orm/task.py

@@ -18,7 +18,8 @@ if TYPE_CHECKING:
 TASK_TYPES = ("note", "measure", "drawing", "dxf_compare", "camera_measure")
 
 # Types the operator screen treats as "there are quotes to take here".
-MEASURING_TASK_TYPES = ("measure", "camera_measure")
+# dxf_compare produce quote come camera_measure (#46)
+MEASURING_TASK_TYPES = ("measure", "camera_measure", "dxf_compare")
 
 
 class RecipeTask(Base):
@@ -51,6 +52,9 @@ class RecipeTask(Base):
     # server routes it and never interprets it, which is what keeps VisionSuite
     # out of this container.
     vision_json: Mapped[Optional[dict]] = mapped_column(JSON, nullable=True)
+    # Cartella immutabile (relativa a upload_path) con recipe.json e i file di
+    # meta della ricetta VisionSuite v2 (#46).
+    vision_recipe_dir: Mapped[Optional[str]] = mapped_column(String(500), nullable=True)
 
     # Relationships
     version: Mapped["RecipeVersion"] = relationship(back_populates="tasks")

src/backend/models/orm/user.py

@@ -22,6 +22,13 @@ class User(Base):
     # Admin flag separate from roles
     is_admin: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
 
+    # PIN a 4 cifre (#59): solo l'hash; contatore errori e fine blocco per il lockout
+    pin_hash: Mapped[Optional[str]] = mapped_column(String(255), nullable=True)
+    pin_failed_count: Mapped[int] = mapped_column(
+        Integer, nullable=False, default=0, server_default="0"
+    )
+    pin_locked_until: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
+
     # User preferences
     language_pref: Mapped[str] = mapped_column(
         Enum("it", "en", name="language_enum"), nullable=False, default="it"
@@ -32,7 +39,6 @@ class User(Base):
 
     # Status
     active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
-    api_key: Mapped[Optional[str]] = mapped_column(String(64), unique=True, nullable=True, index=True)
 
     # Timestamps
     created_at: Mapped[datetime] = mapped_column(
@@ -40,6 +46,11 @@ class User(Base):
     )
     last_login: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
 
+    @property
+    def has_pin(self) -> bool:
+        """True se l'utente ha un PIN impostato (#59); serve a UserResponse.has_pin."""
+        return self.pin_hash is not None
+
     def has_role(self, role: str) -> bool:
         """Check if user has a specific role."""
         return role in (self.roles or [])

src/backend/services/auth_service.py

@@ -1,12 +1,16 @@
 """Authentication service - password hashing, API key management."""
+import hashlib
 import secrets
-from datetime import datetime
+from datetime import datetime, timedelta
+from src.backend.utils.tempo import utcnow
 
 import bcrypt
 from fastapi import HTTPException, status
-from sqlalchemy import select, update
+from sqlalchemy import delete, select, update
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from src.backend.config import settings
+from src.backend.models.orm.api_key import ApiKey
 from src.backend.models.orm.user import User
 
 
@@ -50,7 +54,79 @@ async def authenticate_user(
     return user
 
 
-async def authorise_supervisor(db: AsyncSession, username: str, password: str) -> User:
+# #59: PIN a 4 cifre. Hash identico alle password (bcrypt); 5 errori -> blocco 15 minuti.
+PIN_MAX_FAILURES = 5
+PIN_LOCK_MINUTES = 15
+
+
+async def set_user_pin(db: AsyncSession, user: User, pin: str | None) -> None:
+    """Imposta o toglie (None) il PIN; azzera contatore e blocco. Admin esclusi (#59)."""
+    if pin is not None and user.is_admin:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail="Admin users cannot have a PIN",
+        )
+    user.pin_hash = hash_password(pin) if pin is not None else None
+    user.pin_failed_count = 0
+    user.pin_locked_until = None
+    await db.flush()
+
+
+async def authenticate_pin(db: AsyncSession, user_id: int, pin: str) -> User:
+    """Verifica user_id+PIN con blocco dopo 5 errori consecutivi (#59).
+
+    401 PIN errato (o utente non idoneo: stessa risposta, niente enumerazione),
+    423 utente bloccato. Il contatore va committato prima di sollevare: get_db fa
+    rollback su eccezione e l'errore andrebbe perso.
+    """
+    result = await db.execute(
+        select(User).where(User.id == user_id, User.active == True)  # noqa: E712
+    )
+    user = result.scalar_one_or_none()
+    if user is None or user.is_admin or user.pin_hash is None:
+        verify_password(pin, _DUMMY_PASSWORD_HASH)  # stesso costo di un PIN errato
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid PIN"
+        )
+    now = utcnow()
+    if user.pin_locked_until is not None:
+        if user.pin_locked_until > now:
+            raise HTTPException(
+                status_code=status.HTTP_423_LOCKED,
+                detail="PIN locked until "
+                + user.pin_locked_until.strftime("%Y-%m-%d %H:%M:%S")
+                + " UTC",
+            )
+        # blocco scaduto: si riparte da zero
+        user.pin_locked_until = None
+        user.pin_failed_count = 0
+    if verify_password(pin, user.pin_hash):
+        if user.pin_failed_count:
+            user.pin_failed_count = 0
+            await db.flush()
+        return user
+    user.pin_failed_count += 1
+    locked = user.pin_failed_count >= PIN_MAX_FAILURES
+    if locked:
+        user.pin_locked_until = now + timedelta(minutes=PIN_LOCK_MINUTES)
+    await db.commit()
+    if locked:
+        raise HTTPException(
+            status_code=status.HTTP_423_LOCKED,
+            detail="PIN locked until "
+            + user.pin_locked_until.strftime("%Y-%m-%d %H:%M:%S")
+            + " UTC",
+        )
+    raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid PIN")
+
+
+async def authorise_supervisor(
+    db: AsyncSession,
+    username: str | None = None,
+    password: str | None = None,
+    user_id: int | None = None,
+    pin: str | None = None,
+) -> User:
     """Check the credentials of the supervisor authorising something.
 
     Used wherever the shop floor needs a capoturno: a line stop, a closure, an
@@ -58,10 +134,19 @@ async def authorise_supervisor(db: AsyncSession, username: str, password: str) -
     of them because it is the same question every time - who is this, and are they
     allowed to say yes.
 
-    Uses authenticate_user rather than a full login: logging in would rotate the
-    supervisor's API key and knock out whatever session they have open elsewhere.
+    Uses authenticate_user rather than a full login: logging in would issue a
+    needless API key for the supervisor.
     """
-    supervisor = await authenticate_user(db, username, password)
+    if user_id is not None and pin is not None:
+        # #59: via PIN, stesso blocco del login con PIN (401/423 sollevati da li')
+        supervisor = await authenticate_pin(db, user_id, pin)
+    elif username is not None and password is not None:
+        supervisor = await authenticate_user(db, username, password)
+    else:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail="Supervisor credentials required",
+        )
     if supervisor is None:
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
@@ -75,39 +160,67 @@ async def authorise_supervisor(db: AsyncSession, username: str, password: str) -
     return supervisor
 
 
-async def login_user(db: AsyncSession, user: User) -> str:
-    """Generate (or reuse) the API key and update last_login for user.
+def hash_api_key(key: str) -> str:
+    """SHA-256 hex digest of an API key; this is all the DB ever stores."""
+    return hashlib.sha256(key.encode("utf-8")).hexdigest()
 
-    Reuses an existing key rather than rotating it on every login: the same
-    account logged in from two stations at once (a common shift-account
-    pattern here) must keep both sessions working. Rotating the key would
-    silently log the other station out.
-    """
-    api_key = user.api_key or generate_api_key()
+
+async def issue_api_key(db: AsyncSession, user: User) -> str:
+    """Create a new session key for the user and return it in clear (once)."""
+    key = generate_api_key()
+    now = utcnow()
+    # Housekeeping: drop this user's expired keys so the table does not grow forever.
     await db.execute(
-        update(User)
-        .where(User.id == user.id)
-        .values(api_key=api_key, last_login=datetime.utcnow())
+        delete(ApiKey).where(ApiKey.user_id == user.id, ApiKey.expires_at <= now)
+    )
+    db.add(
+        ApiKey(
+            user_id=user.id,
+            key_hash=hash_api_key(key),
+            created_at=now,
+            expires_at=now + timedelta(hours=settings.api_key_ttl_hours),
+            last_used_at=now,
+        )
+    )
+    await db.flush()
+    return key
+
+
+async def revoke_all_keys(db: AsyncSession, user_id: int) -> None:
+    """Invalidate every session key of a user."""
+    await db.execute(delete(ApiKey).where(ApiKey.user_id == user_id))
+    await db.flush()
+
+
+async def login_user(db: AsyncSession, user: User) -> str:
+    """Issue a new API key for this login and update last_login.
+
+    One key per login: the same account used from several stations at once
+    (#25) keeps every station working, because no login revokes another's key.
+    """
+    api_key = await issue_api_key(db, user)
+    await db.execute(
+        update(User).where(User.id == user.id).values(last_login=utcnow())
     )
     await db.flush()
     return api_key
 
 
 async def logout_user(
-    db: AsyncSession, user: User, all_sessions: bool = False
+    db: AsyncSession, user: User, key: str | None = None, all_sessions: bool = False
 ) -> None:
-    """Log out. By default a no-op on the shared API key.
-
-    Clearing the key on every logout would kick out any other station still
-    using the same shift account. `all_sessions=True` is the explicit
-    override for a supervisor who wants every session logged out.
-    """
-    if not all_sessions:
+    """Log out. Deletes only the key of this session; all_sessions=True
+    deletes every key of the user."""
+    if all_sessions:
+        await revoke_all_keys(db, user.id)
         return
-    await db.execute(
-        update(User).where(User.id == user.id).values(api_key=None)
-    )
-    await db.flush()
+    if key:
+        await db.execute(
+            delete(ApiKey).where(
+                ApiKey.user_id == user.id, ApiKey.key_hash == hash_api_key(key)
+            )
+        )
+        await db.flush()
 
 
 async def create_user(
@@ -138,11 +251,7 @@ async def create_user(
     return user
 
 
-async def regenerate_api_key(db: AsyncSession, user_id: int) -> str:
-    """Regenerate API key for a user."""
-    new_key = generate_api_key()
-    await db.execute(
-        update(User).where(User.id == user_id).values(api_key=new_key)
-    )
-    await db.flush()
-    return new_key
+async def regenerate_api_key(db: AsyncSession, user: User) -> str:
+    """Revoke every key of the user and issue a fresh one."""
+    await revoke_all_keys(db, user.id)
+    return await issue_api_key(db, user)

src/backend/services/measurement_service.py

@@ -1,6 +1,7 @@
 """Measurement service - pass/fail calculation, data storage."""
 import math
 from datetime import datetime
+from src.backend.utils.tempo import utcnow
 from decimal import Decimal
 from typing import TYPE_CHECKING
 
@@ -9,6 +10,7 @@ from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from src.backend.models.orm.measurement import Measurement
+from src.backend.models.orm.production import ProductionEvent
 from src.backend.models.orm.recipe import Recipe, RecipeVersion
 from src.backend.models.orm.task import (
     MEASURING_TASK_TYPES, RecipeSubtask, RecipeTask,
@@ -241,6 +243,73 @@ async def task_progress(
     return progress
 
 
+async def current_cycle_measurements(
+    db: AsyncSession, run_id: int, task_id: int,
+) -> list[dict]:
+    """The quotes of a task already measured in the cycle that is under way.
+
+    A reload, a timer redirect or an auto-logout throws away what the page held in
+    memory; the operator would measure the same quotes again and the duplicates
+    would reach the SPC statistics. The cycle needs no column of its own: it starts
+    at the latest event of the run that opens one for this task - the run start, a
+    cycle_completed, or a remeasure of this task.
+
+    If a task_measured of this task follows that boundary the task is already
+    closed in this cycle and there is nothing to restore. Where a quote was measured
+    more than once, the last reading stands.
+    """
+    boundary = (await db.execute(
+        select(ProductionEvent.id, ProductionEvent.created_at)
+        .where(
+            ProductionEvent.run_id == run_id,
+            (ProductionEvent.event_type.in_(("start", "cycle_completed")))
+            | (
+                (ProductionEvent.event_type == "remeasure")
+                & (ProductionEvent.task_id == task_id)
+            ),
+        )
+        .order_by(ProductionEvent.id.desc())
+        .limit(1)
+    )).first()
+
+    event_filter = [ProductionEvent.run_id == run_id]
+    measurement_filter = [Measurement.production_run_id == run_id]
+    if boundary is not None:
+        boundary_id, boundary_at = boundary
+        event_filter.append(ProductionEvent.id > boundary_id)
+        measurement_filter.append(Measurement.measured_at > boundary_at)
+
+    closed = (await db.execute(
+        select(ProductionEvent.id).where(
+            *event_filter,
+            ProductionEvent.event_type == "task_measured",
+            ProductionEvent.task_id == task_id,
+        ).limit(1)
+    )).first()
+    if closed is not None:
+        return []
+
+    rows = (await db.execute(
+        select(Measurement)
+        .join(RecipeSubtask, RecipeSubtask.id == Measurement.subtask_id)
+        .where(*measurement_filter, RecipeSubtask.task_id == task_id)
+        .order_by(Measurement.measured_at, Measurement.id)
+    )).scalars().all()
+
+    latest: dict[int, Measurement] = {}
+    for m in rows:
+        latest[m.subtask_id] = m
+    return [
+        {
+            "subtask_id": m.subtask_id,
+            "value": float(m.value),
+            "pass_fail": m.pass_fail,
+            "measured_at": m.measured_at,
+        }
+        for m in sorted(latest.values(), key=lambda m: (m.measured_at, m.id))
+    ]
+
+
 async def validate_run_for_version(
     db: AsyncSession, run_id: int, version_id: int,
 ) -> "ProductionRun":
@@ -275,7 +344,7 @@ async def authorise_measurement(
 ) -> Measurement:
     """Let an out-of-tolerance value stand, on the supervisor's name."""
     measurement.supervisor_id = supervisor.id
-    measurement.authorised_at = datetime.now()
+    measurement.authorised_at = utcnow()
     await db.flush()
     await db.refresh(measurement)
     return measurement

src/backend/services/production_export_service.py

@@ -14,6 +14,7 @@ import csv
 import io
 import logging
 from datetime import datetime
+from src.backend.utils.tempo import iso_utc, to_local, utcnow
 from pathlib import Path
 
 from sqlalchemy import select, update
@@ -169,9 +170,9 @@ async def build_statistics_csv(db: AsyncSession, run: ProductionRun) -> str:
             measurement.input_method,
             "" if measurement.input_duration_ms is None else measurement.input_duration_ms,
             measurement.measured_by,
-            measurement.measured_at.isoformat() if measurement.measured_at else "",
+            iso_utc(measurement.measured_at),
             measurement.supervisor_id or "",
-            measurement.authorised_at.isoformat() if measurement.authorised_at else "",
+            iso_utc(measurement.authorised_at),
         ])
 
     return output.getvalue()
@@ -191,7 +192,7 @@ async def export_run_statistics(db: AsyncSession, run: ProductionRun) -> str | N
     directory = Path(settings.upload_path) / EXPORT_SUBDIR
     directory.mkdir(parents=True, exist_ok=True)
 
-    stamp = (run.closed_at or datetime.now()).strftime("%Y%m%d_%H%M%S")
+    stamp = to_local(run.closed_at or utcnow()).strftime("%Y%m%d_%H%M%S")
     filename = f"production_{run.id}_{stamp}.csv"
     # A large run's file can take a moment to write: off the event loop, so
     # closing one run does not stall every other request being served.

src/backend/services/production_service.py

@@ -14,6 +14,7 @@ the countdown would be off by the UTC offset. The number is the contract; the
 timestamp is only there for the audit trail.
 """
 from datetime import datetime, timedelta
+from src.backend.utils.tempo import utcnow
 from typing import Optional
 
 from fastapi import HTTPException, status
@@ -34,10 +35,10 @@ from src.backend.services import (
 def _now() -> datetime:
     """Single source of time for runs.
 
-    Naive local time, matching what the database writes for ``func.now()`` defaults,
+    Naive UTC, matching what the database writes for ``func.now()`` defaults,
     so a run's started_at and its deadline are comparable.
     """
-    return datetime.now()
+    return utcnow()
 
 
 # ---------------------------------------------------------------------------

src/backend/services/recipe_service.py

@@ -115,6 +115,8 @@ async def _copy_tasks_to_version(
             # a camera_measure task unable to execute from the moment a
             # recipe with measurements is next edited.
             vision_json=task.vision_json,
+            # Cartella immutabile: basta il riferimento (#46).
+            vision_recipe_dir=task.vision_recipe_dir,
         )
         db.add(new_task)
         await db.flush()  # get new_task.id

src/backend/services/report_service.py

@@ -2,6 +2,7 @@
 import asyncio
 import base64
 from datetime import datetime
+from src.backend.utils.tempo import to_local, utcnow
 from pathlib import Path
 
 import plotly.graph_objects as go
@@ -32,6 +33,11 @@ _jinja_env = Environment(
 )
 
 
+def _giorno_locale(dt: datetime) -> str:
+    """UTC naive filter bound -> local calendar day (YYYY-MM-DD)."""
+    return to_local(dt).strftime("%Y-%m-%d")
+
+
 async def _query_measurements(
     db: AsyncSession,
     recipe_id: int,
@@ -323,9 +329,9 @@ async def generate_spc_report(
     if version_id:
         filters_desc.append(f"Version: {version_id}")
     if date_from:
-        filters_desc.append(f"From: {date_from.strftime('%Y-%m-%d')}")
+        filters_desc.append(f"From: {_giorno_locale(date_from)}")
     if date_to:
-        filters_desc.append(f"To: {date_to.strftime('%Y-%m-%d')}")
+        filters_desc.append(f"To: {_giorno_locale(date_to)}")
     if lot_number:
         filters_desc.append(f"Lot: {lot_number}")
     if serial_number:
@@ -342,7 +348,7 @@ async def generate_spc_report(
         control_chart_svg=control_chart_svg,
         histogram_svg=histogram_svg,
         filters_desc=filters_desc,
-        generated_at=datetime.now(),
+        generated_at=to_local(utcnow()),
         n_measurements=len(measurements),
     )
 
@@ -395,7 +401,7 @@ async def generate_measurement_report(
             "value": f"{float(m.value):.4f}",
             "unit": st_info.get("unit", "mm"),
             "pass_fail": m.pass_fail,
-            "measured_at": m.measured_at.strftime("%Y-%m-%d %H:%M"),
+            "measured_at": to_local(m.measured_at).strftime("%Y-%m-%d %H:%M"),
             "operator": operator_map.get(m.measured_by, f"ID {m.measured_by}"),
             "lot_number": m.lot_number or "—",
             "serial_number": m.serial_number or "—",
@@ -414,9 +420,9 @@ async def generate_measurement_report(
     if version_id:
         filters_desc.append(f"Version: {version_id}")
     if date_from:
-        filters_desc.append(f"From: {date_from.strftime('%Y-%m-%d')}")
+        filters_desc.append(f"From: {_giorno_locale(date_from)}")
     if date_to:
-        filters_desc.append(f"To: {date_to.strftime('%Y-%m-%d')}")
+        filters_desc.append(f"To: {_giorno_locale(date_to)}")
     if lot_number:
         filters_desc.append(f"Lot: {lot_number}")
     if serial_number:
@@ -430,7 +436,7 @@ async def generate_measurement_report(
         rows=rows,
         summary=summary,
         filters_desc=filters_desc,
-        generated_at=datetime.now(),
+        generated_at=to_local(utcnow()),
         n_measurements=len(measurements),
     )
 

src/backend/services/vision_service.py

@@ -5,6 +5,7 @@ to the worker over HTTP and stays ignorant of how a number was produced.
 """
 from __future__ import annotations
 
+import hashlib
 import json
 import math
 from pathlib import Path
@@ -46,7 +47,13 @@ def _is_measurable(value: object) -> bool:
     )
 
 
-async def _call_worker(image_bytes: bytes, graph: dict) -> dict:
+async def _call_worker(
+    image_bytes: bytes,
+    graph: dict,
+    *,
+    recipe_dir: str | None = None,
+    calibration: dict | None = None,
+) -> dict:
     """The one place that talks to the worker; the tests replace it.
 
     The worker's fault must not become the API's fault (spec's edge-case
@@ -60,12 +67,19 @@ async def _call_worker(image_bytes: bytes, graph: dict) -> dict:
     is not the worker's JSON contract must not turn into a bare KeyError
     further down.
     """
+    # recipe_dir (relativo, #46) e calibration sono opzionali: se assenti non
+    # si mandano, il worker usa i suoi default.
+    data = {"graph": json.dumps(graph)}
+    if recipe_dir:
+        data["recipe_dir"] = recipe_dir
+    if calibration:
+        data["calibration"] = json.dumps(calibration)
     try:
         async with httpx.AsyncClient(timeout=120.0) as client:
             response = await client.post(
                 f"{settings.vision_worker_url}/run",
                 files={"image": ("frame.png", image_bytes, "image/png")},
-                data={"graph": json.dumps(graph)},
+                data=data,
             )
     except httpx.TimeoutException as exc:
         raise HTTPException(
@@ -122,6 +136,180 @@ async def _call_worker(image_bytes: bytes, graph: dict) -> dict:
     return report
 
 
+async def validate_recipe(graph: dict, recipe_dir: str | None) -> dict:
+    """Ask the worker's /validate whether a v2 recipe is loadable (#46).
+
+    Returns {"ok", "errors", "outputs"}. A worker 422 (e.g. recipe_dir
+    refused) is folded into ok=False; transport faults become 502/504 as in
+    `_call_worker`. Replaced by the tests.
+    """
+    data = {"graph": json.dumps(graph)}
+    if recipe_dir:
+        data["recipe_dir"] = recipe_dir
+    try:
+        async with httpx.AsyncClient(timeout=60.0) as client:
+            response = await client.post(
+                f"{settings.vision_worker_url}/validate", data=data,
+            )
+    except httpx.TimeoutException as exc:
+        raise HTTPException(
+            status_code=status.HTTP_504_GATEWAY_TIMEOUT,
+            detail=f"the vision worker did not answer in time: {exc}",
+        ) from exc
+    except httpx.HTTPError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_502_BAD_GATEWAY,
+            detail=f"the vision worker is unreachable: {exc}",
+        ) from exc
+    if response.status_code == status.HTTP_422_UNPROCESSABLE_CONTENT:
+        try:
+            detail = response.json().get("detail", response.text)
+        except ValueError:
+            detail = response.text
+        errors = detail if isinstance(detail, list) else [str(detail)]
+        return {"ok": False, "errors": [str(e) for e in errors], "outputs": []}
+    if response.status_code != 200:
+        raise HTTPException(
+            status_code=status.HTTP_502_BAD_GATEWAY,
+            detail=f"the vision worker refused the job: {response.text}",
+        )
+    try:
+        body = response.json()
+    except ValueError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_502_BAD_GATEWAY,
+            detail="the vision worker's answer was malformed: not valid JSON",
+        ) from exc
+    if not isinstance(body, dict) or "ok" not in body:
+        raise HTTPException(
+            status_code=status.HTTP_502_BAD_GATEWAY,
+            detail="the vision worker's answer was malformed: missing ok",
+        )
+    body.setdefault("errors", [])
+    body.setdefault("outputs", [])
+    return body
+
+
+# Task types that run a vision graph (#46).
+VISION_TASK_TYPES = ("camera_measure", "dxf_compare")
+
+
+def _safe_join(root: Path, relative: str) -> Path:
+    """root/relative, refusing absolute paths, '..' and anything leaving root."""
+    candidate = Path(relative)
+    if candidate.is_absolute() or ".." in candidate.parts or not candidate.parts:
+        raise ValueError(f"unsafe path: {relative}")
+    full = (root / candidate).resolve()
+    if not full.is_relative_to(root.resolve()):
+        raise ValueError(f"unsafe path: {relative}")
+    return full
+
+
+def collect_meta_paths(node: object) -> list[str]:
+    """Every `path` string found in any dict under the recipe's `meta`."""
+    found: list[str] = []
+    if isinstance(node, dict):
+        for key, value in node.items():
+            if key == "path" and isinstance(value, str):
+                found.append(value)
+            else:
+                found.extend(collect_meta_paths(value))
+    elif isinstance(node, list):
+        for item in node:
+            found.extend(collect_meta_paths(item))
+    return found
+
+
+def match_recipe_files(
+    recipe: dict, uploads: list[tuple[str, bytes]],
+) -> tuple[dict[str, bytes], list[str]]:
+    """Pair each uploaded file with a meta path by base name (#46).
+
+    Returns ({relative path: bytes}, errors). Errors list every upload that
+    has no name or matches no meta path, and every unsafe meta path. A meta
+    path left without a file is not an error here: /validate decides.
+    """
+    paths = collect_meta_paths(recipe.get("meta", {}))
+    by_name: dict[str, str] = {}
+    for p in paths:
+        by_name.setdefault(Path(p.replace("\\", "/")).name, p)
+    placed: dict[str, bytes] = {}
+    errors: list[str] = []
+    for name, content in uploads:
+        if not name:
+            errors.append("a file has no name")
+            continue
+        target = by_name.get(Path(name.replace("\\", "/")).name)
+        if target is None:
+            errors.append(f"file {name!r} matches no path in the recipe's meta")
+            continue
+        try:
+            _safe_join(Path("."), target)
+        except ValueError:
+            errors.append(f"meta path {target!r} is not allowed")
+            continue
+        placed[target] = content
+    return placed, errors
+
+
+def store_recipe_folder(
+    task_id: int, recipe: dict, files: dict[str, bytes],
+) -> str:
+    """Write the immutable recipe folder; return its path relative to uploads.
+
+    Folder name = first 16 hex of the recipe's sha256. If it already exists it
+    is left untouched (immutable: other task versions may reference it).
+    """
+    canonical = json.dumps(recipe, sort_keys=True, separators=(",", ":"))
+    digest = hashlib.sha256(canonical.encode("utf-8")).hexdigest()[:16]
+    relative = f"vision/recipes/{task_id}/{digest}"
+    folder = settings.upload_path / relative
+    if folder.exists():
+        return relative
+    folder.mkdir(parents=True, exist_ok=True)
+    (folder / "recipe.json").write_text(
+        json.dumps(recipe, indent=2, ensure_ascii=False), encoding="utf-8",
+    )
+    for rel, content in files.items():
+        target = _safe_join(folder, rel)
+        target.parent.mkdir(parents=True, exist_ok=True)
+        target.write_bytes(content)
+    return relative
+
+
+def list_recipe_files(recipe_dir: str | None) -> list[str]:
+    """Files of a recipe folder, relative to it (recipe.json excluded)."""
+    if not recipe_dir:
+        return []
+    try:
+        folder = _safe_join(settings.upload_path, recipe_dir)
+    except ValueError:
+        return []
+    if not folder.is_dir():
+        return []
+    return sorted(
+        p.relative_to(folder).as_posix()
+        for p in folder.rglob("*") if p.is_file() and p.name != "recipe.json"
+    )
+
+
+def save_result_files(
+    task_id: int, image_bytes: bytes, overlay: list, image_ext: str = "png",
+) -> tuple[str, str]:
+    """Save the executed image and its overlay JSON side by side (#46).
+
+    Returns (image_path, overlay_path), both relative to uploads.
+    """
+    stem = uuid4().hex
+    base = Path("vision") / "results" / str(task_id)
+    (settings.upload_path / base).mkdir(parents=True, exist_ok=True)
+    image_rel = (base / f"{stem}.{image_ext}").as_posix()
+    overlay_rel = (base / f"{stem}.overlay.json").as_posix()
+    (settings.upload_path / image_rel).write_bytes(image_bytes)
+    (settings.upload_path / overlay_rel).write_text(json.dumps(overlay), encoding="utf-8")
+    return image_rel, overlay_rel
+
+
 async def execute_task(
     db: AsyncSession,
     task: RecipeTask,
@@ -132,8 +320,9 @@ async def execute_task(
     lot_number: str | None = None,
     serial_number: str | None = None,
     production_run_id: int | None = None,
-) -> tuple[VisionResult, list[Measurement]]:
-    if task.task_type != "camera_measure":
+    image_ext: str = "png",
+) -> tuple[VisionResult, list[Measurement], dict]:
+    if task.task_type not in VISION_TASK_TYPES:
         raise HTTPException(
             status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
             detail=f"task type {task.task_type!r} is not a camera measurement",
@@ -210,7 +399,11 @@ async def execute_task(
             ),
         )
 
-    report = await _call_worker(image_bytes, task.vision_json)
+    # Nessuna fonte di calibrazione esiste oggi (ne' task ne' stazione): non si
+    # passa `calibration`, la ricetta porta la sua (#46).
+    report = await _call_worker(
+        image_bytes, task.vision_json, recipe_dir=task.vision_recipe_dir,
+    )
     outputs = report["outputs"]
 
     # Every quote or none. A half-measured piece read as a whole one is worse
@@ -231,8 +424,12 @@ async def execute_task(
             ),
         )
 
+    overlay = report.get("overlay") or []
+    image_path, overlay_path = save_result_files(task.id, image_bytes, overlay, image_ext)
     result = VisionResult(
         task_id=task.id,
+        image_path=image_path,
+        overlay_path=overlay_path,
         engine_version=report["engine_version"],
         executed_on="server",
         graph_snapshot=task.vision_json,
@@ -257,7 +454,7 @@ async def execute_task(
             enforce_tolerance_gate=False,
         ))
 
-    return result, saved
+    return result, saved, report
 
 
 def _reference_file_path(reference: VisionReferenceImage) -> Path:
@@ -377,4 +574,6 @@ async def preview(db: AsyncSession, task: RecipeTask, image_bytes: bytes) -> dic
             status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
             detail="this task carries no vision graph",
         )
-    return await _call_worker(image_bytes, task.vision_json)
+    return await _call_worker(
+        image_bytes, task.vision_json, recipe_dir=task.vision_recipe_dir,
+    )

src/backend/tests/conftest.py

@@ -40,7 +40,7 @@ from src.backend.models.orm.measurement import Measurement
 from src.backend.models.orm.access_log import AccessLog
 from src.backend.models.orm.setting import SystemSetting, RecipeVersionAudit
 from src.backend.models.orm.station import Station, StationRecipeAssignment
-from src.backend.services.auth_service import hash_password, generate_api_key
+from src.backend.services.auth_service import hash_password, issue_api_key
 
 # ---------------------------------------------------------------------------
 # In-memory SQLite engine for tests
@@ -142,7 +142,6 @@ async def _create_user(
     active: bool = True,
 ) -> User:
     """Insert a user into the test DB and return it with an API key set."""
-    api_key = generate_api_key()
     user = User(
         username=username,
         password_hash=hash_password(password),
@@ -150,13 +149,14 @@ async def _create_user(
         roles=roles or [],
         is_admin=is_admin,
         active=active,
-        api_key=api_key,
         language_pref="en",
         theme_pref="light",
     )
     session.add(user)
     await session.flush()
     await session.refresh(user)
+    # Clear key of this test session; the DB only keeps its hash.
+    user.plain_key = await issue_api_key(session, user)
     return user
 
 
@@ -278,4 +278,4 @@ async def create_test_recipe(
 
 def auth_headers(user: User) -> dict[str, str]:
     """Return headers dict with the user's API key for authenticated requests."""
-    return {"X-API-Key": user.api_key}
+    return {"X-API-Key": user.plain_key}

src/backend/tests/test_auth.py

@@ -78,75 +78,114 @@ class TestLogin:
         assert len(api_key) >= 32
 
 
-class TestLoginKeyReuse:
-    """login_user reuses an existing api_key instead of rotating it (#25)."""
+class TestLoginKeyPerSession:
+    """Each login issues its own key; none revokes another (#25, #41)."""
 
-    async def test_two_logins_same_user_share_api_key(
+    async def test_two_logins_same_user_get_distinct_valid_keys(
         self, client: AsyncClient, db_session
     ):
-        """Two stations logging in as the same shift account both keep working."""
         await _create_user(db_session, username="twostations", password="TwoStations1")
-        resp1 = await client.post(
-            "/api/auth/login",
-            json={"username": "twostations", "password": "TwoStations1"},
-        )
-        resp2 = await client.post(
-            "/api/auth/login",
-            json={"username": "twostations", "password": "TwoStations1"},
-        )
-        assert resp1.status_code == 200
-        assert resp2.status_code == 200
-        assert resp1.json()["api_key"] == resp2.json()["api_key"]
+        creds = {"username": "twostations", "password": "TwoStations1"}
+        resp1 = await client.post("/api/auth/login", json=creds)
+        resp2 = await client.post("/api/auth/login", json=creds)
+        k1, k2 = resp1.json()["api_key"], resp2.json()["api_key"]
+        assert k1 != k2
+        for k in (k1, k2):
+            resp = await client.get("/api/auth/me", headers={"X-API-Key": k})
+            assert resp.status_code == 200
 
-    async def test_login_generates_key_when_user_has_none(
+    async def test_db_stores_hash_never_clear_key(
         self, client: AsyncClient, db_session
     ):
-        """A user created without an api_key (e.g. via create_user) still gets one."""
-        from src.backend.services.auth_service import create_user
+        from sqlalchemy import select
+        from src.backend.models.orm.api_key import ApiKey
+        from src.backend.services.auth_service import hash_api_key
 
-        await create_user(
-            db_session, username="brandnew", password="BrandNew1",
-            display_name="Brand New",
-        )
+        await _create_user(db_session, username="hashed", password="HashedPass1")
         resp = await client.post(
-            "/api/auth/login",
-            json={"username": "brandnew", "password": "BrandNew1"},
+            "/api/auth/login", json={"username": "hashed", "password": "HashedPass1"}
         )
+        key = resp.json()["api_key"]
+        hashes = (await db_session.execute(select(ApiKey.key_hash))).scalars().all()
+        assert hash_api_key(key) in hashes
+        assert key not in hashes
+        assert all(len(h) == 64 for h in hashes)
+
+    async def test_expired_key_gives_401(self, client: AsyncClient, db_session):
+        from datetime import timedelta
+        from sqlalchemy import update
+        from src.backend.models.orm.api_key import ApiKey
+        from src.backend.services.auth_service import utcnow
+
+        user = await _create_user(db_session, username="expired", password="ExpiredPass1")
+        await db_session.execute(
+            update(ApiKey).values(expires_at=utcnow() - timedelta(minutes=1))
+        )
+        resp = await client.get("/api/auth/me", headers=auth_headers(user))
+        assert resp.status_code == 401
+        assert "expired" in resp.json()["detail"].lower()
+
+    async def test_use_renews_expiry_only_after_interval(
+        self, client: AsyncClient, db_session
+    ):
+        from datetime import timedelta
+        from sqlalchemy import select, update
+        from src.backend.models.orm.api_key import ApiKey
+        from src.backend.services.auth_service import utcnow
+
+        user = await _create_user(db_session, username="renew", password="RenewPass1")
+        headers = auth_headers(user)
+        old = utcnow() - timedelta(hours=10)
+
+        # Recent use: no write, expiry untouched.
+        recent = utcnow() - timedelta(minutes=1)
+        await db_session.execute(
+            update(ApiKey).values(expires_at=old + timedelta(hours=24), last_used_at=recent)
+        )
+        await client.get("/api/auth/me", headers=headers)
+        row = (await db_session.execute(select(ApiKey))).scalar_one()
+        await db_session.refresh(row)
+        assert row.last_used_at == recent
+
+        # Stale last use: expiry is pushed forward.
+        await db_session.execute(
+            update(ApiKey).values(last_used_at=utcnow() - timedelta(minutes=10))
+        )
+        before = utcnow()
+        resp = await client.get("/api/auth/me", headers=headers)
         assert resp.status_code == 200
-        assert resp.json()["api_key"]
+        await db_session.refresh(row)
+        assert row.expires_at >= before + timedelta(hours=23, minutes=59)
 
 
 class TestLogout:
-    """POST /api/auth/logout is a no-op on the shared api_key by default (#25)."""
+    """Logout deletes only this session's key (#41)."""
 
-    async def test_logout_default_keeps_api_key_valid(
-        self, client: AsyncClient, db_session
-    ):
-        user = await _create_user(
-            db_session, username="shared_logout", password="SharedPass1"
-        )
-        headers = auth_headers(user)
-        resp = await client.post("/api/auth/logout", headers=headers)
+    async def test_logout_removes_only_own_key(self, client: AsyncClient, db_session):
+        await _create_user(db_session, username="shared_logout", password="SharedPass1")
+        creds = {"username": "shared_logout", "password": "SharedPass1"}
+        k1 = (await client.post("/api/auth/login", json=creds)).json()["api_key"]
+        k2 = (await client.post("/api/auth/login", json=creds)).json()["api_key"]
+        resp = await client.post("/api/auth/logout", headers={"X-API-Key": k1})
         assert resp.status_code == 204
 
-        # The key is still valid: another station on the same account keeps working.
-        resp = await client.get("/api/auth/me", headers=headers)
-        assert resp.status_code == 200
+        assert (await client.get("/api/auth/me", headers={"X-API-Key": k1})).status_code == 401
+        assert (await client.get("/api/auth/me", headers={"X-API-Key": k2})).status_code == 200
 
-    async def test_logout_all_sessions_invalidates_api_key(
+    async def test_logout_all_sessions_removes_every_key(
         self, client: AsyncClient, db_session
     ):
-        user = await _create_user(
-            db_session, username="shared_logout_all", password="SharedPass1"
-        )
-        headers = auth_headers(user)
+        await _create_user(db_session, username="shared_logout_all", password="SharedPass1")
+        creds = {"username": "shared_logout_all", "password": "SharedPass1"}
+        k1 = (await client.post("/api/auth/login", json=creds)).json()["api_key"]
+        k2 = (await client.post("/api/auth/login", json=creds)).json()["api_key"]
         resp = await client.post(
-            "/api/auth/logout", params={"all_sessions": "true"}, headers=headers
+            "/api/auth/logout", params={"all_sessions": "true"},
+            headers={"X-API-Key": k1},
         )
         assert resp.status_code == 204
-
-        resp = await client.get("/api/auth/me", headers=headers)
-        assert resp.status_code == 401
+        for k in (k1, k2):
+            assert (await client.get("/api/auth/me", headers={"X-API-Key": k})).status_code == 401
 
 
 class TestAuthenticateUserTiming:
@@ -185,3 +224,69 @@ class TestHealthAndAuth:
         resp = await client.get("/api/users")
         assert resp.status_code == 401
         assert "API key" in resp.json()["detail"] or "Missing" in resp.json()["detail"]
+
+
+class TestRevokeAllKeys:
+    """Password change, deactivation and regenerate invalidate every key (#41)."""
+
+    async def _two_keys(self, client, db_session, name):
+        user = await _create_user(db_session, username=name, password="KeysPass123")
+        creds = {"username": name, "password": "KeysPass123"}
+        keys = [
+            (await client.post("/api/auth/login", json=creds)).json()["api_key"]
+            for _ in range(2)
+        ]
+        return user, keys
+
+    async def _all_401(self, client, keys):
+        for k in keys:
+            resp = await client.get("/api/auth/me", headers={"X-API-Key": k})
+            assert resp.status_code == 401
+
+    async def test_password_change_invalidates_all(self, client, db_session, admin_user):
+        user, keys = await self._two_keys(client, db_session, "pwkeys")
+        resp = await client.put(
+            f"/api/users/{user.id}/password",
+            headers=auth_headers(admin_user), json={"password": "NewSecurePass1"},
+        )
+        assert resp.status_code == 200
+        await self._all_401(client, keys)
+
+    async def test_deactivation_invalidates_all(self, client, db_session, admin_user):
+        user, keys = await self._two_keys(client, db_session, "offkeys")
+        resp = await client.delete(
+            f"/api/users/{user.id}", headers=auth_headers(admin_user)
+        )
+        assert resp.status_code == 204
+        await self._all_401(client, keys)
+
+    async def test_regenerate_invalidates_old_keys(self, client, db_session, admin_user):
+        user, keys = await self._two_keys(client, db_session, "regenkeys")
+        resp = await client.post(
+            f"/api/users/{user.id}/regenerate-key", headers=auth_headers(admin_user)
+        )
+        assert resp.status_code == 200
+        await self._all_401(client, keys)
+        new = resp.json()["api_key"]
+        assert (await client.get("/api/auth/me", headers={"X-API-Key": new})).status_code == 200
+
+
+class TestExpiredKeyCleanup:
+    async def test_expired_key_removed_at_next_login(self, client, db_session):
+        from datetime import timedelta
+        from sqlalchemy import select, update
+        from src.backend.models.orm.api_key import ApiKey
+        from src.backend.services.auth_service import hash_api_key, utcnow
+
+        user = await _create_user(db_session, username="cleanup", password="CleanPass123")
+        old_hash = hash_api_key(user.plain_key)
+        await db_session.execute(
+            update(ApiKey).values(expires_at=utcnow() - timedelta(minutes=1))
+        )
+        resp = await client.post(
+            "/api/auth/login", json={"username": "cleanup", "password": "CleanPass123"}
+        )
+        assert resp.status_code == 200
+        hashes = (await db_session.execute(select(ApiKey.key_hash))).scalars().all()
+        assert old_hash not in hashes
+        assert len(hashes) == 1

src/backend/tests/test_current_cycle.py

@@ -0,0 +1,172 @@
+"""#40: after a reload, the quotes already measured in the cycle come back.
+
+The cycle has no column of its own: it opens at the latest start, cycle_completed
+or remeasure-of-this-task event of the run, and a task_measured of the task after
+that boundary means the task is closed in this cycle.
+"""
+from datetime import datetime, timedelta
+
+from httpx import AsyncClient
+from sqlalchemy import select
+
+from src.backend.models.orm.measurement import Measurement
+from src.backend.models.orm.production import ProductionEvent, ProductionRun
+from src.backend.models.orm.recipe import RecipeVersion
+from src.backend.models.orm.station import Station
+from src.backend.models.orm.task import RecipeSubtask, RecipeTask
+from src.backend.tests.conftest import auth_headers, create_test_recipe
+
+T0 = datetime(2026, 10, 1, 8, 0, 0)
+
+
+async def _setup(db, user):
+    recipe = await create_test_recipe(db, user.id)
+    version = (await db.execute(
+        select(RecipeVersion).where(
+            RecipeVersion.recipe_id == recipe.id, RecipeVersion.is_current == True,  # noqa: E712
+        )
+    )).scalar_one()
+    task = (await db.execute(
+        select(RecipeTask).where(RecipeTask.version_id == version.id)
+    )).scalars().first()
+    first = (await db.execute(
+        select(RecipeSubtask).where(RecipeSubtask.task_id == task.id)
+    )).scalars().first()
+    second = RecipeSubtask(
+        task_id=task.id, marker_number=2, description="Quota 2",
+        nominal=10.0, utl=10.5, uwl=10.3, lwl=9.7, ltl=9.5, unit="mm",
+    )
+    db.add(second)
+    station = Station(code="ST-CYC", name="St", active=True, created_by=user.id)
+    db.add(station)
+    await db.commit()
+    run = ProductionRun(
+        station_id=station.id, recipe_id=recipe.id, version_id=version.id,
+        operator_id=user.id, status="running", active_station_id=station.id,
+    )
+    db.add(run)
+    await db.commit()
+    return run, version, task, first, second
+
+
+async def _event(db, run, user, kind, minutes, task_id=None):
+    db.add(ProductionEvent(
+        run_id=run.id, event_type=kind, user_id=user.id, task_id=task_id,
+        created_at=T0 + timedelta(minutes=minutes),
+    ))
+    await db.commit()
+
+
+async def _meas(db, run, version, subtask, user, minutes, value=10.0):
+    db.add(Measurement(
+        subtask_id=subtask.id, version_id=version.id, measured_by=user.id,
+        value=value, pass_fail="pass", production_run_id=run.id,
+        measured_at=T0 + timedelta(minutes=minutes),
+    ))
+    await db.commit()
+
+
+async def _get(client, user, run, task):
+    resp = await client.get(
+        "/api/measurements/current-cycle", headers=auth_headers(user),
+        params={"production_run_id": run.id, "task_id": task.id},
+    )
+    assert resp.status_code == 200
+    return resp.json()["measurements"]
+
+
+async def test_only_second_cycle_after_cycle_completed(
+    client: AsyncClient, db_session, measurement_tec_user,
+):
+    u = measurement_tec_user
+    run, version, task, q1, q2 = await _setup(db_session, u)
+    await _event(db_session, run, u, "start", 0)
+    await _meas(db_session, run, version, q1, u, 1, 10.1)
+    await _meas(db_session, run, version, q2, u, 2, 10.2)
+    await _event(db_session, run, u, "cycle_completed", 3)
+    await _meas(db_session, run, version, q1, u, 4, 10.3)
+
+    rows = await _get(client, u, run, task)
+    assert [(r["subtask_id"], r["value"]) for r in rows] == [(q1.id, 10.3)]
+    assert rows[0]["pass_fail"] == "pass"
+
+
+async def test_last_reading_of_a_quote_wins(
+    client: AsyncClient, db_session, measurement_tec_user,
+):
+    u = measurement_tec_user
+    run, version, task, q1, q2 = await _setup(db_session, u)
+    await _event(db_session, run, u, "start", 0)
+    await _meas(db_session, run, version, q1, u, 1, 10.1)
+    await _meas(db_session, run, version, q1, u, 2, 10.4)
+
+    rows = await _get(client, u, run, task)
+    assert [(r["subtask_id"], r["value"]) for r in rows] == [(q1.id, 10.4)]
+
+
+async def test_remeasure_of_the_task_empties_the_list(
+    client: AsyncClient, db_session, measurement_tec_user,
+):
+    u = measurement_tec_user
+    run, version, task, q1, q2 = await _setup(db_session, u)
+    await _event(db_session, run, u, "start", 0)
+    await _meas(db_session, run, version, q1, u, 1)
+    await _event(db_session, run, u, "remeasure", 2, task_id=task.id)
+
+    assert await _get(client, u, run, task) == []
+
+
+async def test_remeasure_of_another_task_does_not_move_the_boundary(
+    client: AsyncClient, db_session, measurement_tec_user,
+):
+    u = measurement_tec_user
+    run, version, task, q1, q2 = await _setup(db_session, u)
+    other = RecipeTask(
+        version_id=version.id, title="Altro", task_type=task.task_type, order_index=9,
+    )
+    db_session.add(other)
+    await db_session.commit()
+    await _event(db_session, run, u, "start", 0)
+    await _meas(db_session, run, version, q1, u, 1)
+    await _event(db_session, run, u, "remeasure", 2, task_id=other.id)
+
+    assert len(await _get(client, u, run, task)) == 1
+
+
+async def test_task_measured_after_boundary_means_closed(
+    client: AsyncClient, db_session, measurement_tec_user,
+):
+    u = measurement_tec_user
+    run, version, task, q1, q2 = await _setup(db_session, u)
+    await _event(db_session, run, u, "start", 0)
+    await _meas(db_session, run, version, q1, u, 1)
+    await _meas(db_session, run, version, q2, u, 2)
+    await _event(db_session, run, u, "task_measured", 3, task_id=task.id)
+
+    assert await _get(client, u, run, task) == []
+
+
+async def test_task_measured_before_boundary_does_not_close_next_cycle(
+    client: AsyncClient, db_session, measurement_tec_user,
+):
+    u = measurement_tec_user
+    run, version, task, q1, q2 = await _setup(db_session, u)
+    await _event(db_session, run, u, "start", 0)
+    await _event(db_session, run, u, "task_measured", 1, task_id=task.id)
+    await _event(db_session, run, u, "cycle_completed", 2)
+    await _meas(db_session, run, version, q1, u, 3)
+
+    assert len(await _get(client, u, run, task)) == 1
+
+
+async def test_permissions(client: AsyncClient, db_session, measurement_tec_user, maker_user):
+    run, _v, task, _q1, _q2 = await _setup(db_session, measurement_tec_user)
+    params = {"production_run_id": run.id, "task_id": task.id}
+
+    no_key = await client.get("/api/measurements/current-cycle", params=params)
+    assert no_key.status_code in (401, 403)
+
+    forbidden = await client.get(
+        "/api/measurements/current-cycle", headers=auth_headers(maker_user), params=params,
+    )
+    assert forbidden.status_code == 403

src/backend/tests/test_migrations.py

@@ -107,3 +107,64 @@ class TestBaseMigrationNoopsOnExistingSchema:
         assert "image_path" in {
             c["name"] for c in insp.get_columns("recipes")
         }
+
+
+class TestApiKeyHashMigration:
+    """015_api_key_hash: users.api_key -> api_keys table, and back (#41)."""
+
+    def test_015_upgrade_and_downgrade(self, sqlite_database_url):
+        db_path, _ = sqlite_database_url
+        cfg = _alembic_config()
+        command.upgrade(cfg, "head")
+
+        insp = _inspect(db_path)
+        assert "api_keys" in insp.get_table_names()
+        assert "api_key" not in {c["name"] for c in insp.get_columns("users")}
+        assert {c["name"] for c in insp.get_columns("api_keys")} >= {
+            "user_id", "key_hash", "created_at", "expires_at", "last_used_at",
+        }
+
+        command.downgrade(cfg, "014_vision_fk_ondelete")
+        insp = _inspect(db_path)
+        assert "api_keys" not in insp.get_table_names()
+        assert "api_key" in {c["name"] for c in insp.get_columns("users")}
+
+        command.upgrade(cfg, "head")  # and up again
+        assert "api_keys" in _inspect(db_path).get_table_names()
+
+
+class TestVisionRecipeDirMigration:
+    """016_vision_recipe_dir: recipe_tasks.vision_recipe_dir, su e giu (#46)."""
+
+    def test_016_upgrade_and_downgrade(self, sqlite_database_url):
+        db_path, _ = sqlite_database_url
+        cfg = _alembic_config()
+
+        def cols():
+            return {c["name"] for c in _inspect(db_path).get_columns("recipe_tasks")}
+
+        command.upgrade(cfg, "head")
+        assert "vision_recipe_dir" in cols()
+        command.downgrade(cfg, "015_api_key_hash")
+        assert "vision_recipe_dir" not in cols()
+        command.upgrade(cfg, "head")  # e di nuovo su
+        assert "vision_recipe_dir" in cols()
+
+
+class TestUserPinMigration:
+    """017_user_pin: users.pin_hash / pin_failed_count / pin_locked_until, su e giu (#59)."""
+
+    def test_017_upgrade_and_downgrade(self, sqlite_database_url):
+        db_path, _ = sqlite_database_url
+        cfg = _alembic_config()
+        new = {"pin_hash", "pin_failed_count", "pin_locked_until"}
+
+        def cols():
+            return {c["name"] for c in _inspect(db_path).get_columns("users")}
+
+        command.upgrade(cfg, "head")
+        assert new <= cols()
+        command.downgrade(cfg, "016_vision_recipe_dir")
+        assert not (new & cols())
+        command.upgrade(cfg, "head")  # e di nuovo su
+        assert new <= cols()

src/backend/tests/test_pin.py

@@ -0,0 +1,167 @@
+"""PIN a 4 cifre: login rapido, blocco, capoturno via PIN (#59)."""
+from datetime import timedelta
+
+import pytest
+from fastapi import HTTPException
+from httpx import AsyncClient
+from sqlalchemy import select
+
+from src.backend.models.orm.user import User
+from src.backend.services import auth_service
+from src.backend.tests.conftest import _create_user, auth_headers
+from src.backend.tests.test_production_runs import (
+    _open, _recipe_with_interval, _station,
+)
+from src.backend.utils.tempo import utcnow
+
+
+async def _pin_user(db_session, username="operaio", pin="1234", **kw) -> User:
+    user = await _create_user(db_session, username=username, **kw)
+    await auth_service.set_user_pin(db_session, user, pin)
+    await db_session.commit()
+    return user
+
+
+async def _login_pin(client, user_id, pin):
+    return await client.post("/api/auth/login-pin", json={"user_id": user_id, "pin": pin})
+
+
+async def test_login_pin_ok_same_shape_as_login(client: AsyncClient, db_session):
+    user = await _pin_user(db_session)
+    resp = await _login_pin(client, user.id, "1234")
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["user"]["username"] == "operaio"
+    assert data["user"]["has_pin"] is True
+    assert data["api_key"]
+    assert "pin_hash" not in data["user"]
+    # la api_key vale davvero
+    me = await client.get("/api/auth/me", headers={"X-API-Key": data["api_key"]})
+    assert me.status_code == 200
+
+
+async def test_login_pin_wrong_is_401(client: AsyncClient, db_session):
+    user = await _pin_user(db_session)
+    assert (await _login_pin(client, user.id, "9999")).status_code == 401
+
+
+async def test_login_pin_format_422(client: AsyncClient, db_session):
+    user = await _pin_user(db_session)
+    for bad in ("123", "12345", "12a4", ""):
+        assert (await _login_pin(client, user.id, bad)).status_code == 422
+
+
+async def test_lock_after_five_errors_even_with_right_pin(client: AsyncClient, db_session):
+    user = await _pin_user(db_session)
+    for _ in range(4):
+        assert (await _login_pin(client, user.id, "0000")).status_code == 401
+    resp = await _login_pin(client, user.id, "0000")  # 5 errore: scatta il blocco
+    assert resp.status_code == 423
+    assert "locked until" in resp.json()["detail"]
+    assert (await _login_pin(client, user.id, "1234")).status_code == 423
+
+
+async def test_lock_expires_and_counter_resets(client: AsyncClient, db_session):
+    user = await _pin_user(db_session)
+    for _ in range(5):
+        await _login_pin(client, user.id, "0000")
+    row = (await db_session.execute(select(User).where(User.id == user.id))).scalar_one()
+    await db_session.refresh(row)
+    assert row.pin_locked_until > utcnow() + timedelta(minutes=14)
+    # tempo simulato: il blocco e scaduto un secondo fa
+    row.pin_locked_until = utcnow() - timedelta(seconds=1)
+    await db_session.commit()
+    assert (await _login_pin(client, user.id, "1234")).status_code == 200
+    await db_session.refresh(row)
+    assert row.pin_failed_count == 0 and row.pin_locked_until is None
+
+
+async def test_success_resets_failed_counter(client: AsyncClient, db_session):
+    user = await _pin_user(db_session)
+    for _ in range(3):
+        await _login_pin(client, user.id, "0000")
+    assert (await _login_pin(client, user.id, "1234")).status_code == 200
+    for _ in range(4):  # il contatore e ripartito da zero: 4 errori non bloccano
+        assert (await _login_pin(client, user.id, "0000")).status_code == 401
+
+
+async def test_admin_cannot_have_pin_or_login_with_it(client: AsyncClient, admin_user, db_session):
+    resp = await client.put(
+        f"/api/users/{admin_user.id}/pin", headers=auth_headers(admin_user), json={"pin": "1234"},
+    )
+    assert resp.status_code == 422
+    # anche un admin con pin_hash scritto a mano non entra da login-pin
+    admin_user.pin_hash = auth_service.hash_password("1234")
+    await db_session.commit()
+    assert (await _login_pin(client, admin_user.id, "1234")).status_code == 401
+    listed = (await client.get("/api/auth/pin-users")).json()
+    assert all(u["id"] != admin_user.id for u in listed)
+
+
+async def test_put_pin_set_and_remove(client: AsyncClient, admin_user, db_session):
+    user = await _create_user(db_session, username="senzapin")
+    await db_session.commit()
+    h = auth_headers(admin_user)
+    assert (await client.put(f"/api/users/{user.id}/pin", headers=h, json={"pin": "4321"})).status_code == 200
+    assert (await _login_pin(client, user.id, "4321")).status_code == 200
+    assert (await client.put(f"/api/users/{user.id}/pin", headers=h, json={"pin": "12"})).status_code == 422
+    assert (await client.put(f"/api/users/{user.id}/pin", headers=h, json={"pin": None})).status_code == 200
+    assert (await _login_pin(client, user.id, "4321")).status_code == 401
+    assert (await client.put("/api/users/99999/pin", headers=h, json={"pin": "1234"})).status_code == 404
+    # non admin: 403
+    assert (await client.put(
+        f"/api/users/{user.id}/pin", headers=auth_headers(user), json={"pin": "1234"},
+    )).status_code == 403
+
+
+async def test_pin_users_list(client: AsyncClient, db_session):
+    a = await _pin_user(db_session, username="zeta", display_name="Zeta Rossi", pin="1111")
+    b = await _pin_user(db_session, username="alfa", display_name="Alfa Bianchi", pin="2222")
+    await _create_user(db_session, username="nopin")
+    await _pin_user(db_session, username="inattivo", pin="3333", active=False)
+    await db_session.commit()
+    resp = await client.get("/api/auth/pin-users")  # senza autenticazione
+    assert resp.status_code == 200
+    data = resp.json()
+    assert [u["display_name"] for u in data] == ["Alfa Bianchi", "Zeta Rossi"]
+    assert all(set(u) == {"id", "display_name"} for u in data)
+    assert {u["id"] for u in data} == {a.id, b.id}
+
+
+async def test_supervisor_via_pin(client: AsyncClient, measurement_tec_user, admin_user, db_session):
+    station = await _station(db_session, admin_user.id, code="ST-PIN")
+    recipe = await _recipe_with_interval(db_session, admin_user.id, 10, code="REC-PIN")
+    run_id = (await _open(client, measurement_tec_user, station, recipe)).json()["id"]
+    capo = await _pin_user(db_session, username="capo-pin", pin="5555", roles=["Supervisor"])
+    h = auth_headers(measurement_tec_user)
+
+    bad = await client.post(
+        f"/api/production-runs/{run_id}/pause", headers=h,
+        json={"supervisor_user_id": capo.id, "supervisor_pin": "0000"},
+    )
+    assert bad.status_code == 401
+    ok = await client.post(
+        f"/api/production-runs/{run_id}/pause", headers=h,
+        json={"supervisor_user_id": capo.id, "supervisor_pin": "5555"},
+    )
+    assert ok.status_code == 200
+    # nessuna coppia di credenziali: 422
+    none = await client.post(f"/api/production-runs/{run_id}/resume", headers=h, json={})
+    assert none.status_code == 422
+
+
+async def test_supervisor_pin_role_still_checked(db_session):
+    plain = await _pin_user(db_session, username="non-capo", pin="6666", roles=["Maker"])
+    with pytest.raises(HTTPException) as e:
+        await auth_service.authorise_supervisor(db_session, user_id=plain.id, pin="6666")
+    assert e.value.status_code == 403
+
+
+async def test_supervisor_pin_lockout(db_session):
+    capo = await _pin_user(db_session, username="capo-lock", pin="7777", roles=["Supervisor"])
+    codes = []
+    for pin in ["0000"] * 5 + ["7777"]:
+        with pytest.raises(HTTPException) as e:
+            await auth_service.authorise_supervisor(db_session, user_id=capo.id, pin=pin)
+        codes.append(e.value.status_code)
+    assert codes == [401, 401, 401, 401, 423, 423]

src/backend/tests/test_tempo.py

@@ -0,0 +1,113 @@
+"""UTC in the DB, explicit +00:00 on the wire, local time only on presentation (#42)."""
+from datetime import datetime, timezone
+from unittest.mock import patch
+
+from httpx import AsyncClient
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from src.backend.models.orm.user import User
+from src.backend.services import report_service
+from src.backend.tests.conftest import auth_headers, create_test_recipe
+from src.backend.utils.tempo import as_utc_naive, to_local, utcnow
+
+
+def test_utcnow_naive_and_close_to_utc():
+    now = utcnow()
+    assert now.tzinfo is None
+    delta = datetime.now(timezone.utc).replace(tzinfo=None) - now
+    assert abs(delta.total_seconds()) < 5
+
+
+def test_as_utc_naive():
+    parsed = datetime.fromisoformat("2026-10-06T10:00:00+02:00")
+    assert as_utc_naive(parsed) == datetime(2026, 10, 6, 8, 0)
+    assert as_utc_naive(parsed).tzinfo is None
+    naive = datetime(2026, 10, 6, 8, 0)
+    assert as_utc_naive(naive) is naive
+    assert as_utc_naive(None) is None
+
+
+def test_to_local_is_rome():
+    assert to_local(datetime(2026, 10, 6, 8, 0)).strftime("%H:%M %z") == "10:00 +0200"
+    assert to_local(datetime(2026, 1, 6, 8, 0)).strftime("%H:%M %z") == "09:00 +0100"
+
+
+async def _make_measurement(client, user, recipe_id) -> None:
+    tasks = (await client.get(f"/api/recipes/{recipe_id}/tasks", headers=auth_headers(user))).json()
+    await client.post(
+        "/api/measurements/",
+        headers=auth_headers(user),
+        json={
+            "subtask_id": tasks[0]["subtasks"][0]["id"],
+            "version_id": tasks[0]["version_id"],
+            "value": 10.0,
+        },
+    )
+
+
+async def test_api_datetimes_carry_utc_offset_and_filter_equivalence(
+    client: AsyncClient,
+    measurement_tec_user: User,
+    metrologist_user: User,
+    db_session: AsyncSession,
+):
+    recipe = await create_test_recipe(db_session, measurement_tec_user.id)
+    await _make_measurement(client, measurement_tec_user, recipe.id)
+
+    resp = await client.get("/api/measurements/", headers=auth_headers(metrologist_user))
+    item = resp.json()["items"][0]
+    assert item["measured_at"].endswith("+00:00")
+
+    # Same instant written with +02:00 and as UTC: identical results.
+    future_utc = "2099-01-01T08:00:00+00:00"
+    future_rome = "2099-01-01T10:00:00+02:00"
+    past_utc = "2000-01-01T08:00:00+00:00"
+    past_rome = "2000-01-01T10:00:00+02:00"
+    for frm, to in ((past_utc, future_utc), (past_rome, future_rome)):
+        r = await client.get(
+            "/api/measurements/",
+            headers=auth_headers(metrologist_user),
+            params={"date_from": frm, "date_to": to},
+        )
+        assert r.status_code == 200
+        assert r.json()["total"] == 1
+
+    # Boundary: measurement is "now" in UTC; a date_from 1h ahead in UTC,
+    # written as +02:00 (now+3h local wall clock), must exclude it.
+    ahead = (utcnow().replace(microsecond=0)).replace(tzinfo=timezone.utc)
+    from datetime import timedelta
+    ahead_utc = (ahead + timedelta(hours=1)).isoformat()
+    ahead_rome = (ahead + timedelta(hours=1)).astimezone(
+        timezone(timedelta(hours=2))
+    ).isoformat()
+    totals = []
+    for frm in (ahead_utc, ahead_rome):
+        r = await client.get(
+            "/api/measurements/",
+            headers=auth_headers(metrologist_user),
+            params={"date_from": frm},
+        )
+        totals.append(r.json()["total"])
+    assert totals == [0, 0]
+
+
+async def test_report_generated_at_is_local_time(
+    db_session: AsyncSession, metrologist_user: User
+):
+    recipe = await create_test_recipe(db_session, metrologist_user.id)
+    captured: dict[str, str] = {}
+
+    def fake_render(html: str) -> bytes:
+        captured["html"] = html
+        return b"%PDF"
+
+    with patch.object(report_service, "utcnow", return_value=datetime(2026, 10, 6, 8, 0)), \
+            patch.object(report_service, "_render_pdf", side_effect=fake_render):
+        await report_service.generate_measurement_report(db_session, recipe.id)
+
+    assert "Generated 2026-10-06 10:00" in captured["html"]
+
+
+def test_report_filter_day_is_local():
+    """UTC naive 22:00 of Oct 5 is already Oct 6 in Europe/Rome (#42)."""
+    assert report_service._giorno_locale(datetime(2026, 10, 5, 22, 0, 0)) == "2026-10-06"

src/backend/tests/test_user_password_endpoint.py

@@ -17,7 +17,7 @@ class TestChangeUserPassword:
 
         the same as setup.py's change-user-password (setup.py:634).
         """
-        old_key = maker_user.api_key
+        old_key = maker_user.plain_key
         old_username = maker_user.username
         assert old_key is not None
 
@@ -31,7 +31,7 @@ class TestChangeUserPassword:
 
         # The old key no longer authenticates. Read it before the request
         # above: the client and app share one session (see conftest), so
-        # `maker_user.api_key` in this process reflects the mutation too.
+        # `maker_user.plain_key` in this process reflects the mutation too.
         resp2 = await client.get("/api/auth/me", headers={"X-API-Key": old_key})
         assert resp2.status_code == 401
 

src/backend/tests/test_vision_execute.py

@@ -66,7 +66,7 @@ async def two_vision_quotes(db_session, recipe_id: int):
 def worker_says(monkeypatch):
     """The worker does not run in tests: its response is faked here."""
     def _install(outputs: dict, failures: list | None = None):
-        async def fake_call(image_bytes: bytes, graph: dict) -> dict:
+        async def fake_call(image_bytes: bytes, graph: dict, **kwargs) -> dict:
             return {
                 "outputs": outputs,
                 "failures": failures or [],
@@ -316,7 +316,7 @@ async def test_a_pending_fail_blocks_before_the_worker_is_called(
     )
     await db_session.commit()
 
-    async def worker_must_not_be_called(image_bytes: bytes, graph: dict) -> dict:
+    async def worker_must_not_be_called(image_bytes: bytes, graph: dict, **kwargs) -> dict:
         raise AssertionError("the worker must not run while the operator is blocked")
     monkeypatch.setattr(
         "src.backend.services.vision_service._call_worker", worker_must_not_be_called,

src/backend/tests/test_vision_execute_gates.py

@@ -53,7 +53,7 @@ async def a_camera_task(db_session, recipe_id: int):
 @pytest.fixture
 def worker_says(monkeypatch):
     def _install(outputs: dict):
-        async def fake_call(image_bytes: bytes, graph: dict) -> dict:
+        async def fake_call(image_bytes: bytes, graph: dict, **kwargs) -> dict:
             return {"outputs": outputs, "failures": [],
                     "engine_version": "e" * 40, "duration_ms": 3}
         monkeypatch.setattr(

src/backend/tests/test_vision_recipe_upload.py

@@ -0,0 +1,265 @@
+"""Ricetta VisionSuite v2 su un task, execute dxf_compare, copy-on-write (#46)."""
+import io
+import json
+
+import pytest
+from PIL import Image
+from sqlalchemy import select
+
+from src.backend.config import settings
+from src.backend.models.orm.recipe import RecipeVersion
+from src.backend.models.orm.task import RecipeSubtask, RecipeTask
+from src.backend.models.orm.vision import VisionResult
+from src.backend.tests.conftest import auth_headers, create_test_recipe
+
+RECIPE = {
+    "schema_version": 2, "name": "dxf", "tools": [],
+    "meta": {"dxf": {"d1": {"path": "dxf/part.dxf"}}, "models": {"m": {"path": "models/m.npz"}}},
+}
+OUTPUTS = [{"key": "cmp.points_in_pct", "quantity": "ratio", "unit": "%"}]
+GOOD_FILES = (("part.dxf", b"0 EOF"), ("m.npz", b"npz"))
+
+
+@pytest.fixture(autouse=True)
+def redirect_uploads(monkeypatch, tmp_path):
+    # upload_path = parents[2] / upload_dir: un assoluto sostituisce la base
+    monkeypatch.setattr(settings, "upload_dir", str(tmp_path))
+
+
+@pytest.fixture
+def validate_says(monkeypatch):
+    """Il worker /validate non gira nei test: risposta finta."""
+    def _install(ok=True, errors=None, outputs=None):
+        async def fake(graph, recipe_dir):
+            return {
+                "ok": ok, "errors": errors or [],
+                "outputs": outputs if outputs is not None else OUTPUTS,
+            }
+        monkeypatch.setattr("src.backend.services.vision_service.validate_recipe", fake)
+    return _install
+
+
+def an_image() -> bytes:
+    buf = io.BytesIO()
+    Image.new("L", (32, 32)).save(buf, format="PNG")
+    return buf.getvalue()
+
+
+async def make_task(db_session, user, task_type="dxf_compare"):
+    recipe = await create_test_recipe(db_session, user.id)
+    version = (await db_session.execute(
+        select(RecipeVersion).where(RecipeVersion.recipe_id == recipe.id)
+    )).scalars().first()
+    task = (await db_session.execute(
+        select(RecipeTask).where(RecipeTask.version_id == version.id)
+    )).scalars().first()
+    subtask = (await db_session.execute(
+        select(RecipeSubtask).where(RecipeSubtask.task_id == task.id)
+    )).scalars().first()
+    task.task_type = task_type
+    await db_session.commit()
+    return task, subtask
+
+
+def upload(client, user, task, recipe=RECIPE, files=()):
+    return client.post(
+        f"/api/vision/tasks/{task.id}/recipe",
+        headers=auth_headers(user),
+        files=[("recipe", ("r.json", json.dumps(recipe).encode(), "application/json"))]
+        + [("files", (n, c, "application/octet-stream")) for n, c in files],
+    )
+
+
+@pytest.mark.asyncio
+async def test_upload_ok_stores_folder_and_task(client, db_session, maker_user, validate_says):
+    validate_says()
+    task, _ = await make_task(db_session, maker_user)
+    resp = await upload(client, maker_user, task, files=GOOD_FILES)
+    assert resp.status_code == 200, resp.text
+    body = resp.json()
+    assert body["outputs"] == OUTPUTS
+    assert sorted(body["files"]) == ["dxf/part.dxf", "models/m.npz"]
+    assert body["recipe_dir"].startswith(f"vision/recipes/{task.id}/")
+    folder = settings.upload_path / body["recipe_dir"]
+    assert (folder / "recipe.json").is_file() and (folder / "dxf" / "part.dxf").is_file()
+    await db_session.refresh(task)
+    assert task.vision_json == RECIPE and task.vision_recipe_dir == body["recipe_dir"]
+
+    got = await client.get(f"/api/vision/tasks/{task.id}/recipe", headers=auth_headers(maker_user))
+    assert got.status_code == 200
+    assert got.json()["recipe"] == RECIPE and got.json()["outputs"] == OUTPUTS
+
+
+@pytest.mark.asyncio
+async def test_get_without_recipe_is_empty(client, db_session, maker_user, validate_says):
+    validate_says()
+    task, _ = await make_task(db_session, maker_user)
+    got = await client.get(f"/api/vision/tasks/{task.id}/recipe", headers=auth_headers(maker_user))
+    assert got.json() == {
+        "task_id": task.id, "recipe_dir": None, "recipe": None, "files": [], "outputs": [],
+    }
+
+
+@pytest.mark.asyncio
+async def test_unmatched_file_name_is_422_list(client, db_session, maker_user, validate_says):
+    validate_says()
+    task, _ = await make_task(db_session, maker_user)
+    resp = await upload(client, maker_user, task, files=[("other.dxf", b"x")])
+    assert resp.status_code == 422
+    assert isinstance(resp.json()["detail"], list) and "other.dxf" in resp.json()["detail"][0]
+    await db_session.refresh(task)
+    assert task.vision_json is None and task.vision_recipe_dir is None
+
+
+@pytest.mark.asyncio
+async def test_traversal_in_meta_path_is_422(client, db_session, maker_user, validate_says):
+    validate_says()
+    task, _ = await make_task(db_session, maker_user)
+    evil = {"schema_version": 2, "tools": [], "meta": {"dxf": {"d": {"path": "../../evil.dxf"}}}}
+    resp = await upload(client, maker_user, task, recipe=evil, files=[("evil.dxf", b"x")])
+    assert resp.status_code == 422
+    assert not (settings.upload_path.parent / "evil.dxf").exists()
+
+
+@pytest.mark.asyncio
+async def test_wrong_task_type_is_422(client, db_session, maker_user, validate_says):
+    validate_says()
+    task, _ = await make_task(db_session, maker_user, task_type="measure")
+    resp = await upload(client, maker_user, task, files=GOOD_FILES)
+    assert resp.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_invalid_json_is_422(client, db_session, maker_user, validate_says):
+    validate_says()
+    task, _ = await make_task(db_session, maker_user)
+    resp = await client.post(
+        f"/api/vision/tasks/{task.id}/recipe", headers=auth_headers(maker_user),
+        files=[("recipe", ("r.json", b"{nope", "application/json"))],
+    )
+    assert resp.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_worker_not_ok_is_422_and_task_unchanged(client, db_session, maker_user, validate_says):
+    validate_says(ok=False, errors=["meta file missing"])
+    task, _ = await make_task(db_session, maker_user)
+    task.vision_json = {"old": 1}
+    task.vision_recipe_dir = "vision/recipes/old"
+    await db_session.commit()
+    resp = await upload(client, maker_user, task, files=GOOD_FILES)
+    assert resp.status_code == 422
+    assert resp.json()["detail"] == ["meta file missing"]
+    await db_session.refresh(task)
+    assert task.vision_json == {"old": 1} and task.vision_recipe_dir == "vision/recipes/old"
+
+
+@pytest.mark.asyncio
+async def test_existing_folder_is_not_rewritten(client, db_session, maker_user, validate_says):
+    validate_says()
+    task, _ = await make_task(db_session, maker_user)
+    first = (await upload(client, maker_user, task, files=GOOD_FILES)).json()
+    marker = settings.upload_path / first["recipe_dir"] / "dxf" / "part.dxf"
+    marker.write_bytes(b"CHANGED")
+    second = (await upload(client, maker_user, task, files=GOOD_FILES)).json()
+    assert second["recipe_dir"] == first["recipe_dir"]
+    assert marker.read_bytes() == b"CHANGED"
+
+
+@pytest.mark.asyncio
+async def test_upload_requires_maker(
+    client, db_session, maker_user, measurement_tec_user, validate_says,
+):
+    validate_says()
+    task, _ = await make_task(db_session, maker_user)
+    resp = await upload(client, measurement_tec_user, task, files=GOOD_FILES)
+    assert resp.status_code in (401, 403)
+
+
+@pytest.mark.asyncio
+async def test_execute_dxf_compare_saves_files_and_extended_response(
+    client, db_session, measurement_tec_user, monkeypatch,
+):
+    task, subtask = await make_task(db_session, measurement_tec_user)
+    task.vision_json = RECIPE
+    task.vision_recipe_dir = "vision/recipes/1/abc"
+    subtask.vision_output = "cmp.points_in_pct"
+    await db_session.commit()
+    seen = {}
+    overlay = [{"type": "contour", "role": "found", "rows": [1], "cols": [2], "tool_id": "cmp"}]
+
+    async def fake_call(image_bytes, graph, **kwargs):
+        seen.update(kwargs)
+        return {
+            "outputs": {"cmp.points_in_pct": float(subtask.nominal)},
+            "failures": [], "engine_version": "e" * 40, "duration_ms": 5,
+            "overlay": overlay, "outcome": "OK",
+        }
+    monkeypatch.setattr("src.backend.services.vision_service._call_worker", fake_call)
+
+    resp = await client.post(
+        "/api/vision/execute", headers=auth_headers(measurement_tec_user),
+        files={"image": ("p.png", an_image(), "image/png")},
+        data={"task_id": str(task.id)},
+    )
+    assert resp.status_code == 200, resp.text
+    body = resp.json()
+    assert seen["recipe_dir"] == "vision/recipes/1/abc" and "calibration" not in seen
+    assert body["outcome"] == "OK" and body["overlay"] == overlay and body["failures"] == []
+    assert body["image_url"] == f"/api/vision/results/{body['vision_result_id']}/image"
+    assert body["measurements"][0]["pass_fail"] == "pass"
+
+    result = (await db_session.execute(select(VisionResult))).scalars().one()
+    assert (settings.upload_path / result.image_path).read_bytes() == an_image()
+    assert json.loads((settings.upload_path / result.overlay_path).read_text()) == overlay
+
+    img = await client.get(body["image_url"], headers=auth_headers(measurement_tec_user))
+    assert img.status_code == 200 and img.content == an_image()
+
+
+@pytest.mark.asyncio
+async def test_execute_dxf_compare_out_of_tolerance_fails(
+    client, db_session, measurement_tec_user, monkeypatch,
+):
+    task, subtask = await make_task(db_session, measurement_tec_user)
+    task.vision_json = RECIPE
+    subtask.vision_output = "cmp.points_in_pct"
+    await db_session.commit()
+
+    async def fake_call(image_bytes, graph, **kwargs):
+        return {"outputs": {"cmp.points_in_pct": 99.0}, "failures": [],
+                "engine_version": "e" * 40, "outcome": "OK"}
+    monkeypatch.setattr("src.backend.services.vision_service._call_worker", fake_call)
+    resp = await client.post(
+        "/api/vision/execute", headers=auth_headers(measurement_tec_user),
+        files={"image": ("p.png", an_image(), "image/png")},
+        data={"task_id": str(task.id)},
+    )
+    assert resp.status_code == 200
+    # il verdetto e' delle tolleranze del subtask, non di outcome di VisionSuite
+    assert resp.json()["measurements"][0]["pass_fail"] == "fail"
+    assert resp.json()["overlay"] == []
+
+
+@pytest.mark.asyncio
+async def test_copy_on_write_carries_recipe_dir(client, db_session, maker_user):
+    from src.backend.tests.test_vision_copy_on_write import (
+        _current_task_and_subtask, _seed_measurement,
+    )
+    recipe = await create_test_recipe(db_session, maker_user.id)
+    _, task, _ = await _current_task_and_subtask(db_session, recipe.id)
+    task.task_type = "dxf_compare"
+    task.vision_json = RECIPE
+    task.vision_recipe_dir = "vision/recipes/1/abc"
+    await db_session.flush()
+    await _seed_measurement(db_session, recipe.id, maker_user.id)
+    db_session.expunge_all()
+    resp = await client.put(
+        f"/api/recipes/{recipe.id}", headers=auth_headers(maker_user),
+        json={"change_notes": "cow"},
+    )
+    assert resp.status_code == 200
+    db_session.expunge_all()
+    version, new_task, _ = await _current_task_and_subtask(db_session, recipe.id)
+    assert version.version_number == 2
+    assert new_task.vision_recipe_dir == "vision/recipes/1/abc" and new_task.vision_json == RECIPE

src/backend/tests/test_vision_reference.py

@@ -39,7 +39,7 @@ async def recipe_parts(db_session, recipe_id: int):
 @pytest.fixture
 def worker_says(monkeypatch):
     def _install(outputs: dict):
-        async def fake_call(image_bytes: bytes, graph: dict) -> dict:
+        async def fake_call(image_bytes: bytes, graph: dict, **kwargs) -> dict:
             return {"outputs": outputs, "failures": [],
                     "engine_version": "b" * 40, "duration_ms": 7}
         monkeypatch.setattr(

src/backend/tests/test_vision_upload_limits.py

@@ -69,7 +69,7 @@ async def recipe_parts(db_session, recipe_id: int):
 @pytest.fixture
 def worker_says(monkeypatch):
     def _install(outputs: dict):
-        async def fake_call(image_bytes: bytes, graph: dict) -> dict:
+        async def fake_call(image_bytes: bytes, graph: dict, **kwargs) -> dict:
             return {"outputs": outputs, "failures": [],
                     "engine_version": "c" * 40, "duration_ms": 5}
         monkeypatch.setattr(

src/backend/utils/tempo.py

@@ -0,0 +1,34 @@
+"""Time helpers: the DB holds naive UTC, presentation converts to display_timezone (#42)."""
+from datetime import datetime, timezone
+from zoneinfo import ZoneInfo
+
+from src.backend.config import settings
+
+
+def utcnow() -> datetime:
+    """Naive UTC now (the whole DB moves to naive UTC, #42)."""
+    return datetime.now(timezone.utc).replace(tzinfo=None)
+
+
+def as_utc_naive(dt: datetime | None) -> datetime | None:
+    """Aware -> UTC naive; naive is taken as UTC already; None stays None."""
+    if dt is None or dt.tzinfo is None:
+        return dt
+    return dt.astimezone(timezone.utc).replace(tzinfo=None)
+
+
+def to_utc_aware(dt: datetime) -> datetime:
+    """Naive (UTC) or aware datetime -> aware UTC."""
+    if dt.tzinfo is None:
+        return dt.replace(tzinfo=timezone.utc)
+    return dt.astimezone(timezone.utc)
+
+
+def iso_utc(dt: datetime | None) -> str:
+    """ISO 8601 with explicit +00:00; "" for None (CSV cells)."""
+    return to_utc_aware(dt).isoformat() if dt else ""
+
+
+def to_local(dt: datetime) -> datetime:
+    """Naive UTC (or aware) datetime -> aware datetime in settings.display_timezone."""
+    return to_utc_aware(dt).astimezone(ZoneInfo(settings.display_timezone))

src/frontend/flask_app/app.py

@@ -2,7 +2,8 @@
 import json
 import os
 import re
-from datetime import date
+from datetime import date, datetime, timezone
+from zoneinfo import ZoneInfo
 from urllib.parse import urlparse
 
 from flask import Flask, flash, g, jsonify, redirect, url_for, session, request
@@ -154,6 +155,26 @@ def create_app() -> Flask:
         bolded = _BOLD_RX.sub(r"<strong>\1</strong>", escaped)
         return Markup(bolded.replace("\n", "<br>"))
 
+    @app.template_filter("local_dt")
+    def local_dt_filter(value, fmt="%d/%m/%Y %H:%M"):
+        """Show a UTC datetime (ISO string or datetime) in DISPLAY_TIMEZONE.
+
+        A value without timezone is taken as UTC. None or empty gives "-".
+        """
+        if value is None or value == "":
+            return "-"
+        if isinstance(value, str):
+            try:
+                value = datetime.fromisoformat(value.strip().replace("Z", "+00:00"))
+            except ValueError:
+                return value
+        if not isinstance(value, datetime):
+            return str(value)
+        if value.tzinfo is None:
+            value = value.replace(tzinfo=timezone.utc)
+        tz = ZoneInfo(app.config.get("DISPLAY_TIMEZONE") or "Europe/Rome")
+        return value.astimezone(tz).strftime(fmt)
+
     @app.template_filter("tojson_attr")
     def tojson_attr_filter(value):
         """JSON encode safe for HTML attributes (x-data, etc.).

src/frontend/flask_app/blueprints/measure.py

@@ -595,6 +595,40 @@ def api_task_progress(task_id: int):
     return jsonify(row), 200
 
 
+# ---------------------------------------------------------------------------
+# Route: quotes already measured in the current cycle (#40)
+# ---------------------------------------------------------------------------
+@measure_bp.route("/api/current-cycle/<int:task_id>", methods=["GET"])
+@login_required
+@role_required("MeasurementTec")
+def api_current_cycle(task_id: int):
+    """Proxy: quotes of this task already measured in the cycle under way.
+
+    The run comes from _current_run_id(), like the rest of the page. Outside a
+    production there is no cycle to restore and the answer is an empty list.
+    """
+    task_resp = api_client.get(f"/api/tasks/{task_id}")
+    if isinstance(task_resp, dict) and task_resp.get("error"):
+        return jsonify(task_resp), task_resp.get("status_code", 500)
+
+    recipe_id = task_resp.get("recipe_id")
+    if recipe_id and not _recipe_allowed_at_station(recipe_id):
+        abort(403, description=_("Ricetta non assegnata a questa stazione"))
+
+    run_id = _current_run_id()
+    if not run_id:
+        return jsonify({"measurements": []}), 200
+
+    resp = api_client.get(
+        "/api/measurements/current-cycle",
+        params={"production_run_id": run_id, "task_id": task_id},
+    )
+    if not isinstance(resp, dict) or resp.get("error"):
+        # Never fatal: without the restore the screen behaves as it always did.
+        return jsonify({"measurements": []}), 200
+    return jsonify(resp), 200
+
+
 # ---------------------------------------------------------------------------
 # Routes: Out-of-tolerance authorisation (point 5)
 # ---------------------------------------------------------------------------

src/frontend/flask_app/config.py

@@ -56,6 +56,8 @@ class Config:
     # Babel i18n
     BABEL_DEFAULT_LOCALE = "it"
     BABEL_DEFAULT_TIMEZONE = "Europe/Rome"
+    # Il DB e le API parlano UTC; si converte solo alla presentazione.
+    DISPLAY_TIMEZONE: str = os.getenv("DISPLAY_TIMEZONE", "Europe/Rome")
     LANGUAGES = {"it": "Italiano", "en": "English"}
 
 

src/frontend/flask_app/static/js/csv-export.js

@@ -271,7 +271,7 @@ function csvExport() {
      */
     generateFilename(prefix) {
       const now = new Date();
-      const dateStr = now.toISOString().slice(0, 10); // YYYY-MM-DD
+      const dateStr = `${now.getFullYear()}-${String(now.getMonth() + 1).padStart(2, '0')}-${String(now.getDate()).padStart(2, '0')}`; // YYYY-MM-DD locale
       const timeStr = now.toTimeString().slice(0, 5).replace(':', ''); // HHMM
 
       return `${prefix}_${dateStr}_${timeStr}.csv`;

src/frontend/flask_app/templates/measure/task_complete.html

@@ -183,7 +183,7 @@
                     {% for m in measurements|sort(attribute='subtask.marker_number')|sort(attribute='task_info.order_index') %}
                     <tr>
                         <td class="text-center font-mono text-xs" style="color: var(--text-secondary);">
-                            {{ m.measured_at[:16]|replace('T', ' ') if m.measured_at else '-' }}
+                            {{ m.measured_at|local_dt }}
                         </td>
                         <td style="color: var(--text-secondary);" class="text-sm">
                             {{ m.task_info.title if m.task_info else '-' }}

src/frontend/flask_app/templates/measure/task_execute.html

@@ -1100,6 +1100,7 @@ function taskExecute() {
       this.inputStartedAt = Date.now();
       // Rejoin whatever production is already open at this station.
       await this.loadProductionRun();
+      await this.loadCurrentCycle();
       await this.loadPendingAuthorisation();
       // A tablet left to sleep drifts (#37.7): catch the countdown back up to
       // the server's own clock, the same source adoptProductionRun already
@@ -1110,6 +1111,42 @@ function taskExecute() {
       });
     },
 
+    /* Quotes already measured in the cycle under way (#40).
+
+       A reload, a timer redirect or an auto-logout used to bring every quote back
+       and measuring them again put duplicates in the SPC statistics. Only inside
+       a production: outside one there is no cycle, and the screen starts empty as
+       it always did. */
+    async loadCurrentCycle() {
+      if (!this.isMeasureTask || !this.subtasks.length || !this.productionRun) return;
+      try {
+        const resp = await fetch(
+          '{{ url_for("measure.api_current_cycle", task_id=task.id) }}',
+        );
+        if (!resp.ok) return;
+        const data = await resp.json();
+        const known = new Set(this.subtasks.map(s => s.id));
+        const restored = (data.measurements || []).filter(m => known.has(m.subtask_id));
+        if (!restored.length) return;
+        this.measurements = restored.map(m => {
+          const st = this.subtasks.find(s => s.id === m.subtask_id);
+          const nominal = st ? (st.nominal || 0) : 0;
+          return {
+            subtask_id: m.subtask_id,
+            value: m.value,
+            pass_fail: m.pass_fail,
+            deviation: m.value - nominal,
+          };
+        });
+        const next = this.subtasks.findIndex(
+          s => !this.measurements.some(m => m.subtask_id === s.id),
+        );
+        this.currentIndex = next !== -1 ? next : this.subtasks.length - 1;
+      } catch (e) {
+        // Offline: the screen starts empty, as before.
+      }
+    },
+
     /* Is a quote already waiting for the capoturno?
 
        Reloading the page was the simplest way past the old gate. It is not one

src/frontend/flask_app/templates/statistics/dashboard.html

@@ -312,8 +312,8 @@ function spcDashboard() {
       const params = new URLSearchParams();
       params.set('recipe_id', this.selectedRecipeId);
       if (this.selectedSubtaskId) params.set('subtask_id', this.selectedSubtaskId);
-      if (this.dateFrom) params.set('date_from', this.dateFrom + 'T00:00:00');
-      if (this.dateTo) params.set('date_to', this.dateTo + 'T23:59:59');
+      if (this.dateFrom) params.set('date_from', new Date(this.dateFrom + 'T00:00:00').toISOString());
+      if (this.dateTo) params.set('date_to', new Date(this.dateTo + 'T23:59:59.999').toISOString());
 
       try {
         // Parallel fetch of all endpoints
@@ -417,8 +417,8 @@ function spcDashboard() {
         const params = new URLSearchParams();
         params.set('recipe_id', this.selectedRecipeId);
         if (this.selectedSubtaskId) params.set('subtask_id', this.selectedSubtaskId);
-        if (this.dateFrom) params.set('date_from', this.dateFrom + 'T00:00:00');
-        if (this.dateTo) params.set('date_to', this.dateTo + 'T23:59:59');
+        if (this.dateFrom) params.set('date_from', new Date(this.dateFrom + 'T00:00:00').toISOString());
+        if (this.dateTo) params.set('date_to', new Date(this.dateTo + 'T23:59:59.999').toISOString());
 
         const url = '/statistics/api/report-' + type + '?' + params.toString();
         const resp = await fetch(url);

src/frontend/flask_app/tests/test_local_dt.py

@@ -0,0 +1,31 @@
+"""Filtro local_dt: il backend parla UTC, la presentazione e' in Europe/Rome (#42)."""
+from datetime import datetime, timezone
+
+import pytest
+
+
+@pytest.fixture
+def local_dt(flask_app):
+    return flask_app.jinja_env.filters["local_dt"]
+
+
+def test_summer_time(local_dt):
+    assert local_dt("2026-10-06T08:00:00+00:00") == "06/10/2026 10:00"
+
+
+def test_winter_time(local_dt):
+    assert local_dt("2026-01-15T08:00:00+00:00") == "15/01/2026 09:00"
+
+
+def test_naive_is_utc(local_dt):
+    assert local_dt("2026-10-06T08:00:00") == "06/10/2026 10:00"
+
+
+def test_datetime_object_and_format(local_dt):
+    dt = datetime(2026, 10, 6, 8, 0, tzinfo=timezone.utc)
+    assert local_dt(dt, "%H:%M") == "10:00"
+
+
+@pytest.mark.parametrize("empty", [None, ""])
+def test_empty(local_dt, empty):
+    assert local_dt(empty) == "-"

src/frontend/flask_app/tests/test_measure.py

@@ -248,6 +248,67 @@ class TestApiTaskProgress:
         assert resp.status_code in (302, 401)
 
 
+class TestApiCurrentCycle:
+    """GET /measure/api/current-cycle/<task_id> (gitea#40)."""
+
+    @pytest.fixture(autouse=True)
+    def _station_configured(self, monkeypatch):
+        monkeypatch.setattr("blueprints.measure.Config.STATION_CODE", "ST-TEST")
+
+    def test_forwards_run_and_task(self, logged_in_client, mock_api_client):
+        mock_api_client.get_station_recipes.return_value = [{"id": 1}]
+        payload = {"measurements": [
+            {"subtask_id": 3, "value": 10.1, "pass_fail": "pass",
+             "measured_at": "2026-10-01T08:01:00"},
+        ]}
+        mock_api_client.get.side_effect = api_get_router({
+            "/api/tasks/7": {"id": 7, "recipe_id": 1, "version_id": 42},
+            "/api/production-runs/current": {"id": 5},
+            "/api/measurements/current-cycle": payload,
+        })
+
+        resp = logged_in_client.get("/measure/api/current-cycle/7")
+
+        assert resp.status_code == 200
+        assert resp.get_json() == payload
+        call = next(
+            c for c in mock_api_client.get.call_args_list
+            if c.args[0] == "/api/measurements/current-cycle"
+        )
+        assert call.kwargs["params"] == {"production_run_id": 5, "task_id": 7}
+
+    def test_no_run_means_empty_and_no_backend_call(
+        self, logged_in_client, mock_api_client,
+    ):
+        mock_api_client.get_station_recipes.return_value = [{"id": 1}]
+        mock_api_client.get.side_effect = api_get_router({
+            "/api/tasks/7": {"id": 7, "recipe_id": 1, "version_id": 42},
+            "/api/production-runs/current": None,
+        })
+
+        resp = logged_in_client.get("/measure/api/current-cycle/7")
+
+        assert resp.get_json() == {"measurements": []}
+        assert not any(
+            c.args[0] == "/api/measurements/current-cycle"
+            for c in mock_api_client.get.call_args_list
+        )
+
+    def test_refuses_a_recipe_not_assigned_to_this_station(
+        self, logged_in_client, mock_api_client,
+    ):
+        mock_api_client.get_station_recipes.return_value = [{"id": 99}]
+        mock_api_client.get.side_effect = api_get_router({
+            "/api/tasks/7": {"id": 7, "recipe_id": 1, "version_id": 42},
+        })
+
+        assert logged_in_client.get("/measure/api/current-cycle/7").status_code == 403
+
+    def test_requires_login(self, client):
+        resp = client.get("/measure/api/current-cycle/7")
+        assert resp.status_code in (302, 401)
+
+
 class TestStartSequence:
     """GET /measure/start/<recipe_id> — the operator's way in."""
 
@@ -346,6 +407,21 @@ class TestTaskComplete:
         assert resp.status_code == 200
         assert b"productionClock(" in resp.data
 
+    def test_measured_at_shown_in_local_time(self, logged_in_client, mock_api_client):
+        """#42: the API sends UTC; the summary shows Europe/Rome."""
+        mock_api_client.get.side_effect = [
+            {"id": 1, "code": "REC-001", "name": "Test Recipe", "version": 1},
+            [{"id": 1, "title": "Task 1", "order_index": 0, "subtasks": [
+                {"id": 1, "marker_number": 1, "description": "d", "nominal": 1.0,
+                 "unit": "mm"}]}],
+            None,
+            {"items": [{"id": 1, "subtask_id": 1, "value": 1.0, "pass_fail": "pass",
+                        "measured_at": "2026-10-06T08:00:00+00:00"}]},
+        ]
+        resp = logged_in_client.get("/measure/complete/1?version_id=5")
+        assert resp.status_code == 200
+        assert "06/10/2026 10:00" in resp.get_data(as_text=True)
+
     def test_measurements_filtered_by_lot_serial_and_operator(
         self, logged_in_client, mock_api_client,
     ):