feat: implement full context-scoped AI chat UI in AIChatPanel

- Added AIChatPanel component with context header, user and AI message handling.
- Integrated streaming responses via IPC and error handling for chat mutations.
- Enhanced user experience with input handling and auto-scrolling features.
- Updated AppShell to derive AI chat context from the current route.
- Introduced ScrollArea component for better scrolling behavior in various dialogs.
- Added support for Tailwind typography and improved global styles.
- Updated project and task dialogs to utilize ScrollArea for better UX.

src/main/ai/copilot.ts

@@ -5,14 +5,14 @@ import { registerProvider, type AIProvider } from './provider';
 type CopilotClientType = import('@github/copilot-sdk').CopilotClient;
 
 let client: CopilotClientType | null = null;
-let token: string | null = null;
+let isReady = false;
 
 const copilotProvider: AIProvider = {
   name: 'copilot',
   displayName: 'GitHub Copilot',
+  usesExternalAuth: true,
 
-  async initialize(t: string): Promise<boolean> {
-    token = t;
+  async initialize(): Promise<boolean> {
     try {
       // Stop existing client if re-initializing
       if (client) {
@@ -22,32 +22,30 @@ const copilotProvider: AIProvider = {
       }
 
       const { CopilotClient } = await import('@github/copilot-sdk');
+      // No githubToken — uses stored OAuth credentials from Copilot CLI
+      // (authenticate first with `copilot auth login`)
       client = new CopilotClient({
-        githubToken: t,
         autoStart: true,
         autoRestart: true,
         logLevel: 'warning',
       });
       await client.start();
-      console.log('[AI] CopilotClient started successfully');
+      isReady = true;
+      console.log('[AI] CopilotClient started (using CLI OAuth credentials)');
       return true;
     } catch (err) {
       console.error('[AI] Failed to start CopilotClient:', err);
       client = null;
+      isReady = false;
       return false;
     }
   },
 
   isReady(): boolean {
-    return client !== null && token !== null;
+    return isReady && client !== null;
   },
 };
 
-/** Get the raw Copilot token (used by future chat/completion calls). */
-export function getCopilotToken(): string | null {
-  return token;
-}
-
 /** Get the CopilotClient instance (null if not initialized). */
 export function getCopilotClient(): CopilotClientType | null {
   return client;