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/lib/comment.d.ts

@@ -0,0 +1,67 @@
+import Container from './container.js'
+import Node, { NodeProps } from './node.js'
+
+declare namespace Comment {
+  export interface CommentRaws extends Record<string, unknown> {
+    /**
+     * The space symbols before the node.
+     */
+    before?: string
+
+    /**
+     * The space symbols between `/*` and the comment’s text.
+     */
+    left?: string
+
+    /**
+     * The space symbols between the comment’s text.
+     */
+    right?: string
+  }
+
+  export interface CommentProps extends NodeProps {
+    /** Information used to generate byte-to-byte equal node string as it was in the origin input. */
+    raws?: CommentRaws
+    /** Content of the comment. */
+    text: string
+  }
+
+  export { Comment_ as default }
+}
+
+/**
+ * It represents a class that handles
+ * [CSS comments](https://developer.mozilla.org/en-US/docs/Web/CSS/Comments)
+ *
+ * ```js
+ * Once (root, { Comment }) {
+ *   const note = new Comment({ text: 'Note: …' })
+ *   root.append(note)
+ * }
+ * ```
+ *
+ * Remember that CSS comments inside selectors, at-rule parameters,
+ * or declaration values will be stored in the `raws` properties
+ * explained above.
+ */
+declare class Comment_ extends Node {
+  parent: Container | undefined
+  raws: Comment.CommentRaws
+  type: 'comment'
+  /**
+   * The comment's text.
+   */
+  get text(): string
+
+  set text(value: string)
+
+  constructor(defaults?: Comment.CommentProps)
+  assign(overrides: Comment.CommentProps | object): this
+  clone(overrides?: Partial<Comment.CommentProps>): this
+  cloneAfter(overrides?: Partial<Comment.CommentProps>): this
+  cloneBefore(overrides?: Partial<Comment.CommentProps>): this
+}
+
+declare class Comment extends Comment_ {}
+
+export = Comment