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/@testing-library/user-event/dist/esm/event/focus.js

@@ -0,0 +1,31 @@
+import '../utils/dataTransfer/Clipboard.js';
+import { getActiveElement } from '../utils/focus/getActiveElement.js';
+import { isFocusable } from '../utils/focus/isFocusable.js';
+import { findClosest } from '../utils/misc/findClosest.js';
+import { updateSelectionOnFocus } from './selection/updateSelectionOnFocus.js';
+import { wrapEvent } from './wrapEvent.js';
+
+// Browsers do not dispatch FocusEvent if the document does not have focus.
+// TODO: simulate FocusEvent in browsers
+/**
+ * Focus closest focusable element.
+ */ function focusElement(element) {
+    const target = findClosest(element, isFocusable);
+    const activeElement = getActiveElement(element.ownerDocument);
+    if ((target !== null && target !== undefined ? target : element.ownerDocument.body) === activeElement) {
+        return;
+    } else if (target) {
+        wrapEvent(()=>target.focus());
+    } else {
+        wrapEvent(()=>activeElement === null || activeElement === undefined ? undefined : activeElement.blur());
+    }
+    updateSelectionOnFocus(target !== null && target !== undefined ? target : element.ownerDocument.body);
+}
+function blurElement(element) {
+    if (!isFocusable(element)) return;
+    const wasActive = getActiveElement(element.ownerDocument) === element;
+    if (!wasActive) return;
+    wrapEvent(()=>element.blur());
+}
+
+export { blurElement, focusElement };