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/server.js

@@ -0,0 +1,26 @@
+const serverExports = {
+  NextRequest: require('next/dist/server/web/spec-extension/request')
+    .NextRequest,
+  NextResponse: require('next/dist/server/web/spec-extension/response')
+    .NextResponse,
+  ImageResponse: require('next/dist/server/web/spec-extension/image-response')
+    .ImageResponse,
+  userAgentFromString: require('next/dist/server/web/spec-extension/user-agent')
+    .userAgentFromString,
+  userAgent: require('next/dist/server/web/spec-extension/user-agent')
+    .userAgent,
+  URLPattern: require('next/dist/server/web/spec-extension/url-pattern')
+    .URLPattern,
+}
+
+// https://nodejs.org/api/esm.html#commonjs-namespaces
+// When importing CommonJS modules, the module.exports object is provided as the default export
+module.exports = serverExports
+
+// make import { xxx } from 'next/server' work
+exports.NextRequest = serverExports.NextRequest
+exports.NextResponse = serverExports.NextResponse
+exports.ImageResponse = serverExports.ImageResponse
+exports.userAgentFromString = serverExports.userAgentFromString
+exports.userAgent = serverExports.userAgent
+exports.URLPattern = serverExports.URLPattern