fix: resolve TypeScript LSP initialization failure

typescript-language-server requires a valid TypeScript installation to
function. Previously, no initializationOptions were sent during the LSP
initialize request, causing the server to fail with:

  'Could not find a valid TypeScript installation. Please ensure that
  the typescript dependency is installed in the workspace or that a
  valid tsserver.path is specified.'

This fix:
- Adds initializationOptions.tsserver.path resolution that searches for
  TypeScript in: workspace node_modules, global npm install, and npx cache
- Wires initialization_options into the LSP startup flow via LSPServerType
- Updates the install step to proactively install TypeScript globally if
  not found locally

crates/lsp/src/config.rs

@@ -205,7 +205,16 @@ impl LspServerConfig {
             custom_binary_config
         );
 
-        let params = default_init_params(&self.initial_workspace, self.client_name)?;
+        let mut params = default_init_params(&self.initial_workspace, self.client_name)?;
+
+        // Resolve server-specific initialization options (e.g., tsserver.path for TypeScript)
+        let init_options = self
+            .server_type
+            .initialization_options(&self.initial_workspace, executor.path_env_var())
+            .await;
+        if let Some(options) = init_options {
+            params.initialization_options = Some(options);
+        }
 
         Ok(ResolvedLspCommand { command, params })
     }