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/postcss-selector-parser/dist/util/getProp.js

@@ -0,0 +1,18 @@
+"use strict";
+
+exports.__esModule = true;
+exports["default"] = getProp;
+function getProp(obj) {
+  for (var _len = arguments.length, props = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+    props[_key - 1] = arguments[_key];
+  }
+  while (props.length > 0) {
+    var prop = props.shift();
+    if (!obj[prop]) {
+      return undefined;
+    }
+    obj = obj[prop];
+  }
+  return obj;
+}
+module.exports = exports.default;