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/components/navigation.react-server.d.ts

@@ -0,0 +1,13 @@
+declare class ReadonlyURLSearchParams extends URLSearchParams {
+    /** @deprecated Method unavailable on `ReadonlyURLSearchParams`. Read more: https://nextjs.org/docs/app/api-reference/functions/use-search-params#updating-searchparams */
+    append(): void;
+    /** @deprecated Method unavailable on `ReadonlyURLSearchParams`. Read more: https://nextjs.org/docs/app/api-reference/functions/use-search-params#updating-searchparams */
+    delete(): void;
+    /** @deprecated Method unavailable on `ReadonlyURLSearchParams`. Read more: https://nextjs.org/docs/app/api-reference/functions/use-search-params#updating-searchparams */
+    set(): void;
+    /** @deprecated Method unavailable on `ReadonlyURLSearchParams`. Read more: https://nextjs.org/docs/app/api-reference/functions/use-search-params#updating-searchparams */
+    sort(): void;
+}
+export { redirect, permanentRedirect, RedirectType } from './redirect';
+export { notFound } from './not-found';
+export { ReadonlyURLSearchParams };