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/compiled/@edge-runtime/primitives/fetch.d.ts

@@ -0,0 +1,27 @@
+declare class Headers extends globalThis.Headers {
+  /** @deprecated Use [`.getSetCookie()`](https://developer.mozilla.org/en-US/docs/Web/API/Headers/getSetCookie) instead. */
+  getAll?(key: 'set-cookie'): string[]
+}
+
+declare class Request extends globalThis.Request {
+  readonly headers: Headers
+  readonly duplex: string
+}
+
+declare class Response extends globalThis.Response {
+  readonly headers: Headers
+  static json(data: any, init?: ResponseInit): Response
+}
+
+type RequestInfo = string | Request | globalThis.Request
+type RequestInit = globalThis.RequestInit
+declare const fetchImplementation: (
+  info: RequestInfo,
+  init?: RequestInit,
+) => Promise<Response>
+
+declare const FileConstructor: typeof File
+declare const FormDataConstructor: typeof FormData
+declare const WebSocketConstructor: typeof WebSocket
+
+export { FileConstructor as File, FormDataConstructor as FormData, Headers, Request, type RequestInfo, type RequestInit, Response, WebSocketConstructor as WebSocket, fetchImplementation as fetch };