feat: add API key management UI (#716)

* feat: add API key management UI

- Created settings page for users to create, view, and delete API keys
- Added Settings link to app navigation header
- Fixed delete operation return value handling in backend to properly handle asyncpg's None response

* feat: replace browser confirm with dialog for API key deletion

- Added Chakra UI Dialog component for better UX when confirming API key deletion
- Implemented proper focus management with cancelRef for accessibility
- Replaced native browser confirm() with controlled dialog state

* style: format API keys page with consistent line breaks

* feat: auto-select API key text for easier copying

- Added automatic text selection after API key creation to streamline the copy workflow
- Applied className to Code component for DOM targeting

* feat: improve API keys page layout and responsiveness

- Reduced max width from 1200px to 800px for better readability
- Added explicit width constraint to ensure consistent sizing across viewports

* refactor: remove redundant comments from API keys page

server/reflector/db/user_api_keys.py

@@ -84,7 +84,8 @@ class UserApiKeyController:
             (user_api_keys.c.id == key_id) & (user_api_keys.c.user_id == user_id)
         )
         result = await get_database().execute(query)
-        return result > 0
+        # asyncpg returns None for DELETE, consider it success if no exception
+        return result is None or result > 0
 
 
 user_api_keys_controller = UserApiKeyController()