Fix: Update admin credentials on startup instead of only creating once

- Modified create_admin_user() to update existing admin with new credentials
- Removes old admin users when ADMIN_EMAIL changes
- Ensures credential changes from environment variables take effect immediately
- Fixes issue where ADMIN_EMAIL changes were being ignored

backend/app/main.py

@@ -21,7 +21,7 @@ uploads_dir.mkdir(exist_ok=True)
 # Create tables
 Base.metadata.create_all(bind=engine)
 
-# Create admin user if doesn't exist
+# Create or update admin user
 def create_admin_user():
     from app.database.database import SessionLocal
     from app.models.user import User
@@ -29,24 +29,27 @@ def create_admin_user():
     
     db = SessionLocal()
     try:
+        # Check if admin with current email exists
         admin = db.query(User).filter(User.email == settings.admin_email).first()
-        if not admin:
-            try:
-                hashed_password = get_password_hash(settings.admin_password)
-            except Exception as hash_error:
-                print(f"⚠️  Password hashing error: {hash_error}")
-                print("⚠️  Using direct bcrypt hash as fallback...")
-                # Fallback: use bcrypt directly to avoid passlib version issues
-                import bcrypt
-                hashed_password = bcrypt.hashpw(
-                    settings.admin_password.encode('utf-8'),
-                    bcrypt.gensalt()
-                ).decode('utf-8')
         
+        if admin:
+            # Admin exists, update password if needed
+            admin.hashed_password = get_password_hash(settings.admin_password)
+            admin.full_name = settings.admin_full_name
+            db.commit()
+            print(f"ℹ️  Admin user updated: {settings.admin_email}")
+        else:
+            # Delete any other admin users (old ones with different emails)
+            old_admins = db.query(User).filter(User.is_admin == True).all()
+            for old_admin in old_admins:
+                db.delete(old_admin)
+            db.commit()
+            
+            # Create new admin user
             admin = User(
                 email=settings.admin_email,
                 full_name=settings.admin_full_name,
-                hashed_password=hashed_password,
+                hashed_password=get_password_hash(settings.admin_password),
                 is_admin=True,
                 is_active=True,
                 must_change_password=True  # Force password change on first login
@@ -55,8 +58,6 @@ def create_admin_user():
             db.commit()
             print(f"✅ Admin user created: {settings.admin_email}")
             print(f"⚠️  Default password: {settings.admin_password} (CHANGE THIS!)")
-        else:
-            print(f"ℹ️  Admin user already exists: {settings.admin_email}")
     except Exception as e:
         print(f"❌ Error creating admin user: {e}")
         db.rollback()