fix: address final-review hygiene items (pydantic config, cookie alias, argon2 exception scope)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013PphXq1s43DNRj1uWKGXof

backend/app/deps.py

@@ -12,7 +12,7 @@ SESSION_COOKIE_NAME = "qm_session"
 
 
 async def get_current_user(
-    qm_session: str | None = Cookie(default=None),
+    qm_session: str | None = Cookie(default=None, alias=SESSION_COOKIE_NAME),
     db: AsyncSession = Depends(get_db),
 ) -> User:
     if qm_session is None:

backend/app/routes/auth.py

@@ -65,7 +65,7 @@ async def login(payload: LoginRequest, response: Response, db: AsyncSession = De
 @router.post("/logout", status_code=status.HTTP_204_NO_CONTENT)
 async def logout(
     response: Response,
-    qm_session: str | None = Cookie(default=None),
+    qm_session: str | None = Cookie(default=None, alias=SESSION_COOKIE_NAME),
     db: AsyncSession = Depends(get_db),
 ):
     if qm_session is not None:

backend/app/schemas.py

@@ -1,6 +1,6 @@
 import uuid
 
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 
 
 class RegisterRequest(BaseModel):
@@ -13,8 +13,7 @@ class UserOut(BaseModel):
     id: uuid.UUID
     username: str
 
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 
 class LoginRequest(BaseModel):

backend/app/security.py

@@ -1,5 +1,5 @@
 from argon2 import PasswordHasher
-from argon2.exceptions import VerifyMismatchError
+from argon2.exceptions import VerificationError
 
 _hasher = PasswordHasher()
 
@@ -11,5 +11,5 @@ def hash_password(password: str) -> str:
 def verify_password(password: str, password_hash: str) -> bool:
     try:
         return _hasher.verify(password_hash, password)
-    except VerifyMismatchError:
+    except VerificationError:
         return False