fix: Error handling for chats that are slow to respond

[erichare]

This pull request adds user feedback and robust error handling for slow or unresponsive chat requests in the chat UI. It introduces a "waiting too long" indicator if the server takes more than 20 seconds to respond, and implements a 60-second timeout for chat requests. Additionally, error messages are now more descriptive and user-friendly, helping users understand the nature of any issues encountered.

User feedback and UI improvements:

• Added a waitingTooLong state and a corresponding UI indicator in ChatPage to inform users when the server is taking longer than expected (after 20 seconds). This indicator provides feedback about possible server load and impending timeout. [1] [2] [3]
• The "waiting too long" indicator is reset appropriately when a response is received or an error occurs. [1] [2]

Timeouts and error handling:

• Implemented a 60-second timeout for chat requests in useChatStreaming, aborting the request and providing a clear error if no response is received in time. The timeout resets with each data chunk received. [1] [2] [3] [4]
• Improved error handling in useChatStreaming to distinguish between different failure scenarios (timeout, no response, network error, server error) and show user-friendly error messages. [1] [2]