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/server/web/spec-extension/unstable-cache.d.ts

@@ -0,0 +1,11 @@
+type Callback = (...args: any[]) => Promise<any>;
+/**
+ * This function allows you to cache the results of expensive operations, like database queries, and reuse them across multiple requests.
+ *
+ * Read more: [Next.js Docs: `unstable_cache`](https://nextjs.org/docs/app/api-reference/functions/unstable_cache)
+ */
+export declare function unstable_cache<T extends Callback>(cb: T, keyParts?: string[], options?: {
+    revalidate?: number | false;
+    tags?: string[];
+}): T;
+export {};