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/internal-utils.d.ts

@@ -0,0 +1,11 @@
+/// <reference types="node" />
+import type { IncomingHttpHeaders } from 'http';
+import type { NextParsedUrlQuery } from './request-meta';
+export declare function stripInternalQueries(query: NextParsedUrlQuery): void;
+export declare function stripInternalSearchParams<T extends string | URL>(url: T, isEdge: boolean): T;
+/**
+ * Strip internal headers from the request headers.
+ *
+ * @param headers the headers to strip of internal headers
+ */
+export declare function stripInternalHeaders(headers: IncomingHttpHeaders): void;