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/dto/provider/request.rs

@@ -17,6 +17,13 @@ pub struct ChatRequest {
     pub top_p: Option<f32>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub stop: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub stream_options: Option<StreamOptions>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct StreamOptions {
+    pub include_usage: bool,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]