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/model/mod.rs

@@ -1,6 +1,8 @@
+pub mod app_config;
 pub mod editlog;
 pub mod memory;
 pub mod msglog;
 pub mod session;
+pub mod session_lock;
 pub mod settings;
 pub mod store;

src/model/msglog/mod.rs

@@ -1,6 +1,8 @@
+pub mod blobs;
 pub mod query;
 pub mod schema;
 
+pub use blobs::store_blob;
 pub use query::insert_message;
 
 pub fn open_or_create(session_dir: &std::path::Path) -> anyhow::Result<rusqlite::Connection> {