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/has-property-descriptors/index.js

@@ -0,0 +1,22 @@
+'use strict';
+
+var $defineProperty = require('es-define-property');
+
+var hasPropertyDescriptors = function hasPropertyDescriptors() {
+	return !!$defineProperty;
+};
+
+hasPropertyDescriptors.hasArrayLengthDefineBug = function hasArrayLengthDefineBug() {
+	// node v0.6 has a bug where array lengths can be Set but not Defined
+	if (!$defineProperty) {
+		return null;
+	}
+	try {
+		return $defineProperty([], 'length', { value: 1 }).length !== 1;
+	} catch (e) {
+		// In Firefox 4-22, defining length on an array throws an exception.
+		return true;
+	}
+};
+
+module.exports = hasPropertyDescriptors;