API key come hash SHA-256, una per sessione, TTL rinnovabile (#41)

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

src/backend/api/routers/auth.py

@@ -1,5 +1,5 @@
 """Authentication router - login, logout, profile."""
-from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi import APIRouter, Depends, HTTPException, Request, status
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from src.backend.database import get_db
@@ -34,15 +34,16 @@ async def login(data: LoginRequest, db: AsyncSession = Depends(get_db)):
 
 @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)