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/autoprefixer/lib/hacks/grid-column-align.js

@@ -0,0 +1,28 @@
+let Declaration = require('../declaration')
+
+class GridColumnAlign extends Declaration {
+  /**
+   * Do not prefix flexbox values
+   */
+  check(decl) {
+    return !decl.value.includes('flex-') && decl.value !== 'baseline'
+  }
+
+  /**
+   * Change IE property back
+   */
+  normalize() {
+    return 'justify-self'
+  }
+
+  /**
+   * Change property name for IE
+   */
+  prefixed(prop, prefix) {
+    return prefix + 'grid-column-align'
+  }
+}
+
+GridColumnAlign.names = ['grid-column-align']
+
+module.exports = GridColumnAlign