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>

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, revoke_all_keys
+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"])
 
@@ -151,6 +157,30 @@ async def change_user_password(
     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,