added loggin to api endpoint

backend/app/routers/auth.py

@@ -1,5 +1,7 @@
 """FluentGerman.ai — Auth router."""
 
+import logging
+
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -9,21 +11,32 @@ from app.database import get_db
 from app.models import User
 from app.schemas import LoginRequest, Token, UserOut
 
+logger = logging.getLogger("fluentgerman.auth")
+
 router = APIRouter(prefix="/api/auth", tags=["auth"])
 
 
 @router.post("/login", response_model=Token)
 async def login(body: LoginRequest, db: AsyncSession = Depends(get_db)):
+    logger.info("Login attempt: username=%s", body.username)
+
     result = await db.execute(select(User).where(User.username == body.username))
     user = result.scalar_one_or_none()
 
-    if not user or not verify_password(body.password, user.hashed_password):
+    if not user:
+        logger.warning("Login failed: user '%s' not found", body.username)
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid credentials")
+
+    if not verify_password(body.password, user.hashed_password):
+        logger.warning("Login failed: wrong password for '%s'", body.username)
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid credentials")
 
     if not user.is_active:
+        logger.warning("Login failed: account '%s' is disabled", body.username)
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Account disabled")
 
     token = create_access_token({"sub": str(user.id)})
+    logger.info("Login success: user=%s admin=%s", user.username, user.is_admin)
     return Token(access_token=token)