phsl / new-api

- Refactor message saving strategy from automatic to manual saving
  - Save messages only on key operations: send, complete, edit, delete, role toggle, clear
  - Prevent frequent localStorage writes during streaming responses

- Remove excessive console logging
  - Remove all console.log statements from save/load operations
  - Clean up debug logs to reduce console noise

- Optimize initial state loading with lazy initialization
  - Replace useRef with useState lazy initialization for config and messages
  - Ensure loadConfig and loadMessages are called only once on mount
  - Prevent redundant localStorage reads during re-renders

- Update hooks to support new save strategy
  - Pass saveMessages callback through component hierarchy
  - Add saveMessagesImmediately to relevant hooks (useApiRequest, useMessageActions, useMessageEdit)
  - Trigger saves at appropriate lifecycle points

This significantly improves performance by reducing localStorage I/O operations
from continuous writes during streaming to discrete saves at meaningful points.