Backend: move JWT logic to deps.py, fix circular import in auth

Token creation/decoding/blacklisting was split across auth.py and deps.py
causing a circular import. Consolidate make_token, decode_token, and
blacklist_token in deps.py; auth.py now imports from there.
Also switches /login to accept JSON body (username+pin) instead of
form-encoded, and returns a proper user object in the response.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

local_backend/routers/auth.py

@@ -1,49 +1,22 @@
-import jwt
 import bcrypt
-from datetime import datetime, timedelta, timezone
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.orm import Session
 
 from database import get_db
-from config import settings
 from models.user import User
 from schemas.auth import LoginRequest, TokenResponse
 from schemas.user import UserOut
+from routers.deps import get_current_user, make_token, decode_token, blacklist_token
 
 router = APIRouter()
 
-TOKEN_EXPIRY_HOURS = 8
-# In-memory token blacklist (cleared on restart — acceptable for local use)
-_blacklisted_tokens: set[str] = set()
-
-
-def _make_token(user: User) -> str:
-    payload = {
-        "sub": str(user.id),
-        "username": user.username,
-        "role": user.role,
-        "exp": datetime.now(timezone.utc) + timedelta(hours=TOKEN_EXPIRY_HOURS),
-    }
-    return jwt.encode(payload, settings.SECRET_KEY, algorithm="HS256")
-
-
-def decode_token(token: str) -> dict:
-    if token in _blacklisted_tokens:
-        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Token revoked")
-    try:
-        return jwt.decode(token, settings.SECRET_KEY, algorithms=["HS256"])
-    except jwt.ExpiredSignatureError:
-        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Token expired")
-    except jwt.InvalidTokenError:
-        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token")
-
 
 @router.post("/login", response_model=TokenResponse)
 def login(body: LoginRequest, db: Session = Depends(get_db)):
     user = db.query(User).filter(User.username == body.username, User.is_active == True).first()
     if not user or not bcrypt.checkpw(body.pin.encode(), user.pin_hash.encode()):
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid credentials")
-    token = _make_token(user)
+    token = make_token(user)
     return TokenResponse(access_token=token, user=UserOut.model_validate(user))
 
 
@@ -53,17 +26,17 @@ def refresh(token: str, db: Session = Depends(get_db)):
     user = db.query(User).filter(User.id == int(payload["sub"]), User.is_active == True).first()
     if not user:
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="User not found")
-    _blacklisted_tokens.add(token)
-    new_token = _make_token(user)
+    blacklist_token(token)
+    new_token = make_token(user)
     return TokenResponse(access_token=new_token, user=UserOut.model_validate(user))
 
 
 @router.post("/logout")
 def logout(token: str):
-    _blacklisted_tokens.add(token)
+    blacklist_token(token)
     return {"status": "logged out"}
 
 
 @router.get("/me", response_model=UserOut)
-def me(db: Session = Depends(get_db), user: User = Depends(get_current_user)):
+def me(user: User = Depends(get_current_user)):
     return user