Fix bcrypt incompatibility: replace passlib with direct bcrypt 5.x API

Dockerfile

@@ -17,7 +17,7 @@ RUN python -m pip install --upgrade pip && \
         alembic \
         psycopg2-binary \
         httpx \
-        passlib[bcrypt] \
+        bcrypt \
         itsdangerous
 
 ## Copy application source code and migration scripts into container

db_async.py

@@ -11,7 +11,7 @@ from databases import Database
 from sqlalchemy import MetaData, Table, Column, Integer, String, Float, DateTime, text
 from sqlalchemy import Index, BigInteger, JSON, Boolean, UniqueConstraint
 from sqlalchemy.sql import func
-from passlib.hash import bcrypt
+import bcrypt as _bcrypt
 
 # Environment: Postgres/TimescaleDB connection URL
 DATABASE_URL = os.getenv(
@@ -364,7 +364,7 @@ async def seed_users():
             },
         ]
         for u in default_users:
-            pw_hash = bcrypt.hash(u["password"])
+            pw_hash = _bcrypt.hashpw(u["password"].encode(), _bcrypt.gensalt()).decode()
             await database.execute(
                 "INSERT INTO users (username, password_hash, is_admin) VALUES (:username, :password_hash, :is_admin)",
                 {

main.py

@@ -42,7 +42,7 @@ from pydantic import BaseModel
 from typing import Optional
 from starlette.middleware.base import BaseHTTPMiddleware
 import httpx
-from passlib.hash import bcrypt
+import bcrypt as _bcrypt
 from itsdangerous import URLSafeTimedSerializer, BadSignature, SignatureExpired
 
 # Async database support
@@ -1314,7 +1314,7 @@ async def login(request: Request):
         "SELECT id, username, password_hash, is_admin FROM users WHERE LOWER(username) = :username",
         {"username": username},
     )
-    if not row or not bcrypt.verify(password, row["password_hash"]):
+    if not row or not _bcrypt.checkpw(password.encode(), row["password_hash"].encode()):
         raise HTTPException(status_code=401, detail="Invalid username or password")
 
     token = create_session_cookie(row["username"], row["is_admin"])
@@ -1401,7 +1401,7 @@ async def create_user(request: Request):
     if existing:
         raise HTTPException(status_code=409, detail="Username already exists")
 
-    pw_hash = bcrypt.hash(password)
+    pw_hash = _bcrypt.hashpw(password.encode(), _bcrypt.gensalt()).decode()
     await database.execute(
         "INSERT INTO users (username, password_hash, is_admin) VALUES (:username, :password_hash, :is_admin)",
         {"username": username, "password_hash": pw_hash, "is_admin": is_admin},
@@ -1442,7 +1442,7 @@ async def update_user(user_id: int, request: Request):
             raise HTTPException(
                 status_code=400, detail="Password must be at least 4 characters"
             )
-        pw_hash = bcrypt.hash(password)
+        pw_hash = _bcrypt.hashpw(password.encode(), _bcrypt.gensalt()).decode()
         await database.execute(
             "UPDATE users SET password_hash = :pw WHERE id = :id",
             {"pw": pw_hash, "id": user_id},