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/preact/compat/src/hooks.js

@@ -0,0 +1,67 @@
+import { useState, useLayoutEffect, useEffect } from 'preact/hooks';
+import { is } from './util';
+
+/**
+ * This is taken from https://github.com/facebook/react/blob/main/packages/use-sync-external-store/src/useSyncExternalStoreShimClient.js#L84
+ * on a high level this cuts out the warnings, ... and attempts a smaller implementation
+ * @typedef {{ _value: any; _getSnapshot: () => any }} Store
+ */
+export function useSyncExternalStore(subscribe, getSnapshot) {
+	const value = getSnapshot();
+
+	/**
+	 * @typedef {{ _instance: Store }} StoreRef
+	 * @type {[StoreRef, (store: StoreRef) => void]}
+	 */
+	const [{ _instance }, forceUpdate] = useState({
+		_instance: { _value: value, _getSnapshot: getSnapshot }
+	});
+
+	useLayoutEffect(() => {
+		_instance._value = value;
+		_instance._getSnapshot = getSnapshot;
+
+		if (didSnapshotChange(_instance)) {
+			forceUpdate({ _instance });
+		}
+	}, [subscribe, value, getSnapshot]);
+
+	useEffect(() => {
+		if (didSnapshotChange(_instance)) {
+			forceUpdate({ _instance });
+		}
+
+		return subscribe(() => {
+			if (didSnapshotChange(_instance)) {
+				forceUpdate({ _instance });
+			}
+		});
+	}, [subscribe]);
+
+	return value;
+}
+
+/** @type {(inst: Store) => boolean} */
+function didSnapshotChange(inst) {
+	try {
+		return !is(inst._value, inst._getSnapshot());
+	} catch (error) {
+		return true;
+	}
+}
+
+export function startTransition(cb) {
+	cb();
+}
+
+export function useDeferredValue(val) {
+	return val;
+}
+
+export function useTransition() {
+	return [false, startTransition];
+}
+
+// TODO: in theory this should be done after a VNode is diffed as we want to insert
+// styles/... before it attaches
+export const useInsertionEffect = useLayoutEffect;