Fix backend bugs: password hash column rename, dynamic import, AuditLog response_model, websocket reference, missing exports, bcrypt version pin

backend/app/routers/admin.py

@@ -184,7 +184,7 @@ async def list_logs(
     ]
 
 
-@router.post("/audit", response_model=AuditLog)
+@router.post("/audit", response_model=dict)
 async def log_audit(
     action_type: str,
     target_user_id: Optional[int] = None,
@@ -210,4 +210,11 @@ async def log_audit(
     db.add(new_audit)
     await db.flush()
     
-    return AuditLog.model_validate(new_audit)
+    return {
+        "id": new_audit.id,
+        "admin_id": new_audit.admin_id,
+        "action_type": new_audit.action_type,
+        "target_user_id": new_audit.target_user_id,
+        "details": new_audit.details,
+        "timestamp": new_audit.timestamp,
+    }

backend/app/routers/auth.py

@@ -4,6 +4,8 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 from typing import Optional
 
+from datetime import datetime
+
 from app.core.database import get_db
 from app.core.security import (
     verify_password,
@@ -33,7 +35,7 @@ async def login(request: LoginRequest, db: AsyncSession = Depends(get_db)):
     result = await db.execute(stmt)
     user = result.scalar_one_or_none()
     
-    if not user or not verify_password(request.password, user.password_sha512):
+    if not user or not verify_password(request.password, user.password_hash):
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail="Invalid username or password",
@@ -120,7 +122,7 @@ async def register(request: UserCreate, db: AsyncSession = Depends(get_db)):
     # Create new user
     new_user = User(
         username=request.username,
-        password_sha512=hash_password(request.password),
+        password_hash=hash_password(request.password),
         salt="random_salt",  # In production, generate random salt
         email=request.email,
         country=request.country,

backend/app/routers/users.py

@@ -62,7 +62,7 @@ async def update_user(
     
     # Hash new password if provided
     if "new_password" in update_data:
-        update_data["password_sha512"] = hash_password(update_data.pop("new_password"))
+        update_data["password_hash"] = hash_password(update_data.pop("new_password"))
     
     # Update user
     stmt = (