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/rest.rs

@@ -12,6 +12,7 @@ use tokio::sync::RwLock;
 use super::misc::{DirCache, InputState, MiscState, ScrollState};
 use super::runtime::{SessionRuntime, TurnEvent};
 use super::types::{Origin, Toast, TranscriptCache};
+use crate::app::lsp::LspManager;
 use crate::app::mcp::manager::McpManager;
 use crate::app::workflow::engine::WorkflowEngine;
 use crate::model::app_config::AppConfig;
@@ -66,6 +67,7 @@ pub struct AppStateRest {
     pub abort_flag: Arc<std::sync::atomic::AtomicBool>,
     pub workflow_engine: WorkflowEngine,
     pub mcp_manager: McpManager,
+    pub lsp_manager: Arc<Mutex<LspManager>>,
     pub dirty: bool,
     pub quit: bool,
 }
@@ -117,6 +119,7 @@ impl AppStateRest {
             session_runtime: Some(SessionRuntime::new(session_dir.clone())),
             workflow_engine: WorkflowEngine::new(),
             mcp_manager: McpManager::new(),
+            lsp_manager: Arc::new(Mutex::new(LspManager::new())),
             sessions: Vec::new(),
             transcript_cache: TranscriptCache::new(200),
             scroll: ScrollState::new(),
@@ -196,6 +199,7 @@ impl AppStateRest {
             dir_cache: self.dir_cache.clone(),
             origin,
             graduated_checks: Vec::new(),
+            lsp_manager: self.lsp_manager.clone(),
         }
     }
 }