Add side panels, task selection, graph animation, and project docs

- Foldable left panel (user profile) and right panel (task details)
- Clicking a task in the list or graph node selects it and shows details
- Both views (task list + graph) always mounted via absolute inset-0 for
  correct canvas dimensions; tabs toggle visibility with opacity
- Graph node selection animation: other nodes repel outward (charge -600),
  then selected node smoothly slides to center (500ms cubic ease-out),
  then charge restores to -120 and graph stabilizes
- Graph re-fits on tab switch and panel resize via ResizeObserver
- Fix UUID string IDs throughout (backend returns UUIDs, not integers)
- Add TaskDetailPanel, UserPanel components
- Add CLAUDE.md project documentation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/node_modules/next/dist/client/dev/hot-middleware-client.d.ts

@@ -0,0 +1,8 @@
+declare const _default: (mode: 'webpack' | 'turbopack') => {
+    subscribeToHmrEvent(handler: any): void;
+    onUnrecoverableError(): void;
+    addTurbopackMessageListener(cb: (msg: import("../../server/dev/hot-reloader-types").TurbopackMsgToBrowser) => void): void;
+    sendTurbopackMessage(msg: string): void;
+    handleUpdateError(err: unknown): void;
+};
+export default _default;