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/aria-query/lib/etc/roles/dpub/docChapterRole.js

@@ -0,0 +1,34 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var docChapterRole = {
+  abstract: false,
+  accessibleNameRequired: false,
+  baseConcepts: [],
+  childrenPresentational: false,
+  nameFrom: ['author'],
+  prohibitedProps: [],
+  props: {
+    'aria-disabled': null,
+    'aria-errormessage': null,
+    'aria-expanded': null,
+    'aria-haspopup': null,
+    'aria-invalid': null
+  },
+  relatedConcepts: [{
+    concept: {
+      name: 'chapter [EPUB-SSV]'
+    },
+    module: 'EPUB'
+  }],
+  requireContextRole: [],
+  requiredContextRole: [],
+  requiredOwnedElements: [],
+  requiredProps: {},
+  superClass: [['roletype', 'structure', 'section', 'landmark']]
+};
+var _default = docChapterRole;
+exports.default = _default;