NextGraph integration (WIP), broker banner, and feature-based architecture

- Add NextGraph data layer with @ng-org/orm, SHEX shapes (Event, UserProfile,
  Participation), session management, and FestipodDataContext with dual-mode
  operation (connected via NextGraph or local seed data)
- Add BrokerBanner and NgStatus components showing connection status
- Refactor to feature-based architecture: organize code by business domain
  (event, user, home, auth, workshop, meeting, notification) instead of
  technical layer. Modules only import from shared/, never from each other
- Collocate BDD features and step definitions with their modules: event-specific
  steps in event/steps/, user steps in user/steps/, shared generic steps remain
  in shared/steps/
- Set up multi-layer BDD structure (frontend/backend/e2e steps per module)
- Add project documentation (AGENTS.md, .project/knowledge/)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/router.tsx

@@ -0,0 +1,127 @@
+import React, { createContext, useContext, useState, useEffect, useCallback } from 'react';
+
+type Route =
+  | { page: 'gallery' }
+  | { page: 'demo'; screenId: string }
+  | { page: 'specs'; featureId?: string; storyId?: string };
+
+interface RouterContextValue {
+  route: Route;
+  navigate: (route: Route) => void;
+  goBack: () => void;
+}
+
+const RouterContext = createContext<RouterContextValue | null>(null);
+
+function parseHash(hash: string): Route {
+  const path = hash.replace(/^#\/?/, '') || '/';
+
+  if (path === '/' || path === '') {
+    return { page: 'gallery' };
+  }
+
+  // Redirect /stories to /specs (backward compatibility)
+  if (path === 'stories') {
+    return { page: 'specs' };
+  }
+
+  // Redirect /stories/{id} to /specs with storyId (backward compatibility)
+  if (path.startsWith('stories/')) {
+    const storyId = path.replace('stories/', '');
+    if (storyId) {
+      return { page: 'specs', storyId };
+    }
+  }
+
+  if (path.startsWith('demo/')) {
+    const screenId = path.replace('demo/', '');
+    if (screenId) {
+      return { page: 'demo', screenId };
+    }
+  }
+
+  if (path === 'specs') {
+    return { page: 'specs' };
+  }
+
+  if (path.startsWith('specs/')) {
+    const featureId = path.replace('specs/', '');
+    if (featureId) {
+      return { page: 'specs', featureId };
+    }
+  }
+
+  return { page: 'gallery' };
+}
+
+function routeToHash(route: Route): string {
+  switch (route.page) {
+    case 'gallery':
+      return '#/';
+    case 'demo':
+      return `#/demo/${route.screenId}`;
+    case 'specs':
+      if (route.featureId) return `#/specs/${route.featureId}`;
+      if (route.storyId) return `#/specs/${route.storyId}`;
+      return '#/specs';
+  }
+}
+
+export function RouterProvider({ children }: { children: React.ReactNode }) {
+  const [route, setRoute] = useState<Route>(() => parseHash(window.location.hash));
+
+  useEffect(() => {
+    const handleHashChange = () => {
+      setRoute(parseHash(window.location.hash));
+    };
+
+    window.addEventListener('hashchange', handleHashChange);
+    return () => window.removeEventListener('hashchange', handleHashChange);
+  }, []);
+
+  const navigate = useCallback((newRoute: Route) => {
+    window.location.hash = routeToHash(newRoute);
+  }, []);
+
+  const goBack = useCallback(() => {
+    window.history.back();
+  }, []);
+
+  return (
+    <RouterContext.Provider value={{ route, navigate, goBack }}>
+      {children}
+    </RouterContext.Provider>
+  );
+}
+
+export function useRouter() {
+  const context = useContext(RouterContext);
+  if (!context) {
+    throw new Error('useRouter must be used within a RouterProvider');
+  }
+  return context;
+}
+
+export function useNavigate() {
+  const { navigate } = useRouter();
+  return navigate;
+}
+
+export function useGoBack() {
+  const { goBack } = useRouter();
+  return goBack;
+}
+
+/**
+ * Generate a URL for a specific story (now redirects to specs)
+ */
+export function getStoryUrl(storyId: string): string {
+  return `#/specs/${storyId}`;
+}
+
+/**
+ * Generate a URL for a specific feature spec
+ */
+export function getSpecUrl(featureId: string): string {
+  return `#/specs/${featureId}`;
+}