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/model/conversation.rs

@@ -10,8 +10,8 @@ pub struct Conversation {
     pub system_prompt: String,
     pub session_id: String,
     pub model: String,
-    pub max_tokens: u32,
-    pub temperature: f32,
+    pub max_tokens: Option<u32>,
+    pub temperature: Option<f32>,
 }
 
 impl Conversation {
@@ -23,8 +23,8 @@ impl Conversation {
             system_prompt,
             session_id,
             model: "anthropic/claude-opus-4-8".to_string(),
-            max_tokens: 8192,
-            temperature: 0.7,
+            max_tokens: None,
+            temperature: None,
         }
     }