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/package.json

@@ -0,0 +1,35 @@
+{
+  "name": "taskpile-frontend",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build",
+    "start": "next start",
+    "test": "jest",
+    "test:unit": "jest --testPathPattern=unit",
+    "test:e2e": "jest --testPathPattern=e2e"
+  },
+  "dependencies": {
+    "next": "14.2.3",
+    "react": "^18",
+    "react-dom": "^18",
+    "react-force-graph-2d": "^1.25.5"
+  },
+  "devDependencies": {
+    "typescript": "^5",
+    "@types/react": "^18",
+    "@types/react-dom": "^18",
+    "@types/node": "^20",
+    "tailwindcss": "^3",
+    "postcss": "^8",
+    "autoprefixer": "^10",
+    "jest": "^29",
+    "@testing-library/react": "^14",
+    "@testing-library/jest-dom": "^6",
+    "@testing-library/user-event": "^14",
+    "jest-environment-jsdom": "^29",
+    "@types/jest": "^29",
+    "ts-jest": "^29"
+  }
+}