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/document/copySelection.js

@@ -0,0 +1,27 @@
+import { createDataTransfer } from '../utils/dataTransfer/DataTransfer.js';
+import '../utils/dataTransfer/Clipboard.js';
+import { getWindow } from '../utils/misc/getWindow.js';
+import { hasOwnSelection } from '../utils/focus/selection.js';
+import { getUISelection, getUIValue } from './UI.js';
+
+function copySelection(target) {
+    const data = hasOwnSelection(target) ? {
+        'text/plain': readSelectedValueFromInput(target)
+    } : {
+        'text/plain': String(target.ownerDocument.getSelection())
+    };
+    const dt = createDataTransfer(getWindow(target));
+    for(const type in data){
+        if (data[type]) {
+            dt.setData(type, data[type]);
+        }
+    }
+    return dt;
+}
+function readSelectedValueFromInput(target) {
+    const sel = getUISelection(target);
+    const val = getUIValue(target);
+    return val.substring(sel.startOffset, sel.endOffset);
+}
+
+export { copySelection };