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/array-buffer-byte-length/index.js

@@ -0,0 +1,14 @@
+'use strict';
+
+var callBound = require('call-bound');
+var $byteLength = callBound('ArrayBuffer.prototype.byteLength', true);
+
+var isArrayBuffer = require('is-array-buffer');
+
+/** @type {import('.')} */
+module.exports = function byteLength(ab) {
+	if (!isArrayBuffer(ab)) {
+		return NaN;
+	}
+	return $byteLength ? $byteLength(ab) : ab.byteLength;
+}; // in node < 0.11, byteLength is an own nonconfigurable property