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/esm/lib/realpath.js

@@ -0,0 +1,9 @@
+import fs from "fs";
+const isWindows = process.platform === "win32";
+// Interesting learning from this, that fs.realpathSync is 70x slower than fs.realpathSync.native:
+// https://sun0day.github.io/blog/vite/why-vite4_3-is-faster.html#fs-realpathsync-issue
+// https://github.com/nodejs/node/issues/2680
+// However, we can't use fs.realpathSync.native on Windows due to behavior differences.
+export const realpathSync = isWindows ? fs.realpathSync : fs.realpathSync.native;
+
+//# sourceMappingURL=realpath.js.map