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/@babel/code-frame/README.md

@@ -0,0 +1,19 @@
+# @babel/code-frame
+
+> Generate errors that contain a code frame that point to source locations.
+
+See our website [@babel/code-frame](https://babeljs.io/docs/babel-code-frame) for more information.
+
+## Install
+
+Using npm:
+
+```sh
+npm install --save-dev @babel/code-frame
+```
+
+or using yarn:
+
+```sh
+yarn add @babel/code-frame --dev
+```