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/app/state/misc.rs

@@ -277,6 +277,8 @@ pub struct MiscState {
     pub selected_index: usize,
     pub editor: Option<super::super::mode::editor::EditorState>,
     pub api_connected: bool,
+    #[allow(dead_code)]
+    pub api_context_length: Option<u32>,
     pub tick_count: u64,
     pub todo_content: String,
 }
@@ -294,6 +296,7 @@ impl MiscState {
             selected_index: 0,
             editor: None,
             api_connected: false,
+            api_context_length: None,
             tick_count: 0,
             todo_content: String::new(),
         }