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/react-dom/README.md

@@ -0,0 +1,60 @@
+# `react-dom`
+
+This package serves as the entry point to the DOM and server renderers for React. It is intended to be paired with the generic React package, which is shipped as `react` to npm.
+
+## Installation
+
+```sh
+npm install react react-dom
+```
+
+## Usage
+
+### In the browser
+
+```js
+import { createRoot } from 'react-dom/client';
+
+function App() {
+  return <div>Hello World</div>;
+}
+
+const root = createRoot(document.getElementById('root'));
+root.render(<App />);
+```
+
+### On the server
+
+```js
+import { renderToPipeableStream } from 'react-dom/server';
+
+function App() {
+  return <div>Hello World</div>;
+}
+
+function handleRequest(res) {
+  // ... in your server handler ...
+  const stream = renderToPipeableStream(<App />, {
+    onShellReady() {
+      res.statusCode = 200;
+      res.setHeader('Content-type', 'text/html');
+      stream.pipe(res);
+    },
+    // ...
+  });
+}
+```
+
+## API
+
+### `react-dom`
+
+See https://reactjs.org/docs/react-dom.html
+
+### `react-dom/client`
+
+See https://reactjs.org/docs/react-dom-client.html
+
+### `react-dom/server`
+
+See https://reactjs.org/docs/react-dom-server.html