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/view/markdown.rs

@@ -1,7 +1,7 @@
 use ratatui::style::{Color, Modifier, Style};
 use ratatui::text::Span;
 
-pub fn render_markdown<'a>(text: &'a str, width: u16) -> Vec<Span<'a>> {
+pub fn render_markdown(text: &str, width: u16) -> Vec<Span<'static>> {
     let mut spans = Vec::new();
     let parser = pulldown_cmark::Parser::new(text);
     let mut in_code_block = false;
@@ -122,6 +122,7 @@ pub fn render_markdown<'a>(text: &'a str, width: u16) -> Vec<Span<'a>> {
         let mut spans_out = Vec::new();
         let mut line_len = 0;
         for span in &spans {
+            let style = span.style;
             let s = span.content.clone();
             let text = s.as_ref();
             let remaining = text.len();
@@ -129,7 +130,7 @@ pub fn render_markdown<'a>(text: &'a str, width: u16) -> Vec<Span<'a>> {
                 spans_out.push(Span::raw("\n"));
                 line_len = 0;
             }
-            spans_out.push(Span::raw(text.to_string()));
+            spans_out.push(Span::styled(text.to_string(), style));
             if !text.contains('\n') {
                 line_len += remaining;
             } else {