feat: add editing and MCP command handling, enhance SSE streaming with usage tracking

- Implemented `Edit` and `McpAdd` commands in the command parser and handler.
- Added a new `stream` module to the runtime for handling streaming events.
- Enhanced `SseParser` to parse usage information from SSE events.
- Introduced `ToolCallAccumulator` for tracking tool calls independently.
- Updated `AppStateRest` to include `app_config` and `MiscState` to track `effort_level` and `selected_index`.
- Modified `LlmClient` to support streaming responses with usage tracking.
- Improved error handling and retry logic in the streaming API calls.
- Added tests for new features and improved markdown rendering in the chat view.

src/app/mode/mod.rs

@@ -1,7 +1,14 @@
 use serde::{Deserialize, Serialize};
 
 pub mod bash;
+pub mod editor;
+pub mod effort;
+pub mod key_input;
+pub mod mcp;
+pub mod onboard;
+pub mod onboard_provider;
 pub mod quit_confirm;
+pub mod rewind;
 pub mod security;
 pub mod settings;
 pub mod todo;