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/lodash-es/_castArrayLikeObject.js

@@ -0,0 +1,14 @@
+import isArrayLikeObject from './isArrayLikeObject.js';
+
+/**
+ * Casts `value` to an empty array if it's not an array like object.
+ *
+ * @private
+ * @param {*} value The value to inspect.
+ * @returns {Array|Object} Returns the cast array-like object.
+ */
+function castArrayLikeObject(value) {
+  return isArrayLikeObject(value) ? value : [];
+}
+
+export default castArrayLikeObject;