feat(lsp): implement LSP client and server management

- Added LspClient for handling communication with LSP servers, including methods for initialization, notifications, and requests.
- Introduced LspManager to manage multiple LSP server connections, allowing for connection, disconnection, and retrieval of server capabilities.
- Created tools for connecting to LSP servers, retrieving diagnostics, hover information, code completion, definitions, and references.
- Enhanced UI rendering to display token usage and settings in the overlay.
- Updated status bar to show current token usage and selected provider/model.

src/view/mod.rs

@@ -142,11 +142,11 @@ fn render_overlay(frame: &mut Frame, area: Rect, overlay: crate::app::state::typ
                     Style::default().fg(Theme::TEXT),
                 )),
                 Line::from(Span::styled(
-                    format!("Max tokens: {}", state.settings.max_tokens),
+                    format!("Max tokens: {}", state.settings.max_tokens.map(|v| v.to_string()).unwrap_or_else(|| "auto".to_string())),
                     Style::default().fg(Theme::TEXT),
                 )),
                 Line::from(Span::styled(
-                    format!("Temperature: {:.1}", state.settings.temperature),
+                    format!("Temperature: {}", state.settings.temperature.map(|v| format!("{:.1}", v)).unwrap_or_else(|| "auto".to_string())),
                     Style::default().fg(Theme::TEXT),
                 )),
                 Line::from(Span::styled(