feat: add dev server log panel with real-time streaming

Add the ability to view dev server logs in a dedicated panel with:
- Real-time log streaming via WebSocket events
- ANSI color support using xterm.js
- Scrollback buffer (50KB) for log history on reconnect
- Output throttling to prevent UI flooding
- "View Logs" option in worktree dropdown menu

Server changes:
- Add scrollback buffer and event emission to DevServerService
- Add GET /api/worktree/dev-server-logs endpoint
- Add dev-server:started, dev-server:output, dev-server:stopped events

UI changes:
- Add reusable XtermLogViewer component
- Add DevServerLogsPanel dialog component
- Add useDevServerLogs hook for WebSocket subscription

Closes #462

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

libs/types/src/event.ts

@@ -42,6 +42,9 @@ export type EventType =
   | 'ideation:idea-converted'
   | 'worktree:init-started'
   | 'worktree:init-output'
-  | 'worktree:init-completed';
+  | 'worktree:init-completed'
+  | 'dev-server:started'
+  | 'dev-server:output'
+  | 'dev-server:stopped';
 
 export type EventCallback = (type: EventType, payload: unknown) => void;