feat: timer intervallo misura su ricetta + auto-logout per inattività

- Recipe: nuovo campo measurement_interval_minutes (migration 003) con UI nel recipe editor
- Auto-logout: impostazione di sistema configurabile da admin/settings, timer inattività JS
  con warning modale 60s prima del logout, tracking eventi utente throttled
- Navbar: aggiunto link "Impostazioni" per admin (desktop + mobile)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/backend/migrations/versions/003_add_measurement_interval_and_auto_logout.py

@@ -0,0 +1,24 @@
+"""add measurement_interval_minutes to recipes
+
+Revision ID: 003_measurement_interval
+Revises: 002_add_stations
+Create Date: 2026-05-23
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = '003_measurement_interval'
+down_revision: Union[str, None] = '002_add_stations'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column('recipes', sa.Column('measurement_interval_minutes', sa.SmallInteger(), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column('recipes', 'measurement_interval_minutes')

src/backend/models/api/recipe.py

@@ -14,6 +14,7 @@ class RecipeCreate(BaseModel):
     name: str = Field(..., min_length=1, max_length=255)
     description: Optional[str] = None
     image_path: Optional[str] = Field(None, max_length=500)
+    measurement_interval_minutes: Optional[int] = Field(None, ge=1, le=1440)
     # Optional task-level fields for the initial technical drawing
     file_path: Optional[str] = Field(None, max_length=500)
     file_type: Optional[str] = Field(None, pattern="^(image|pdf)$")
@@ -25,6 +26,7 @@ class RecipeUpdate(BaseModel):
     name: Optional[str] = Field(None, min_length=1, max_length=255)
     description: Optional[str] = None
     image_path: Optional[str] = Field(None, max_length=500)
+    measurement_interval_minutes: Optional[int] = Field(None, ge=1, le=1440)
     change_notes: Optional[str] = None
     # Task-level fields: saved to the first task of the new version
     file_path: Optional[str] = Field(None, max_length=500)
@@ -55,6 +57,7 @@ class RecipeResponse(BaseModel):
     name: str
     description: Optional[str] = None
     image_path: Optional[str] = None
+    measurement_interval_minutes: Optional[int] = None
     created_by: int
     created_at: datetime
     active: bool

src/backend/models/orm/recipe.py

@@ -2,7 +2,7 @@
 from datetime import datetime
 from typing import TYPE_CHECKING, Optional
 
-from sqlalchemy import Boolean, DateTime, ForeignKey, Index, Integer, String, Text, UniqueConstraint, func
+from sqlalchemy import Boolean, DateTime, ForeignKey, Index, Integer, SmallInteger, String, Text, UniqueConstraint, func
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from src.backend.database import Base
@@ -24,6 +24,7 @@ class Recipe(Base):
         DateTime, nullable=False, server_default=func.now()
     )
     active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True, index=True)
+    measurement_interval_minutes: Mapped[Optional[int]] = mapped_column(SmallInteger, nullable=True)
 
     # Relationships
     versions: Mapped[list["RecipeVersion"]] = relationship(

src/backend/services/recipe_service.py

@@ -134,6 +134,7 @@ async def create_recipe(
         name=data.name,
         description=data.description,
         image_path=data.image_path,
+        measurement_interval_minutes=data.measurement_interval_minutes,
         created_by=user.id,
     )
     db.add(recipe)
@@ -273,6 +274,8 @@ async def create_new_version(
         update_fields["description"] = data.description
     if data.image_path is not None:
         update_fields["image_path"] = data.image_path
+    if data.measurement_interval_minutes is not None:
+        update_fields["measurement_interval_minutes"] = data.measurement_interval_minutes
     if update_fields:
         await db.execute(
             update(Recipe).where(Recipe.id == recipe_id).values(**update_fields)
@@ -369,6 +372,8 @@ async def update_current_version(
         update_fields["description"] = data.description
     if data.image_path is not None:
         update_fields["image_path"] = data.image_path
+    if data.measurement_interval_minutes is not None:
+        update_fields["measurement_interval_minutes"] = data.measurement_interval_minutes
     if update_fields:
         await db.execute(
             update(Recipe).where(Recipe.id == recipe_id).values(**update_fields)