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/_mapCacheSet.js

@@ -0,0 +1,22 @@
+import getMapData from './_getMapData.js';
+
+/**
+ * Sets the map `key` to `value`.
+ *
+ * @private
+ * @name set
+ * @memberOf MapCache
+ * @param {string} key The key of the value to set.
+ * @param {*} value The value to set.
+ * @returns {Object} Returns the map cache instance.
+ */
+function mapCacheSet(key, value) {
+  var data = getMapData(this, key),
+      size = data.size;
+
+  data.set(key, value);
+  this.size += data.size == size ? 0 : 1;
+  return this;
+}
+
+export default mapCacheSet;