feat(demo): app launch UIs, "No demo" gating, onboarding skip, 12 nodes

App launching (DEMO):
- resolveAppUrl routes every app to its demo target: mock UIs for Bitcoin Core,
  ElectrumX, Fedimint (served by the backend), IndeeHub → iframe indee.tx1138.com,
  Mempool → mempool.space/testnet (new tab); all others → a generic "Demo preview"
  notice page.
- Non-demoable apps show a disabled "No demo" install button (marketplace details,
  app grid, featured apps).

Onboarding:
- Demo treats the visitor as fully set up so the onboarding WIZARD (seed/identity)
  is never forced; the welcome intro still replays per day. Intro CTA goes straight
  to login; wizard entry points + login restart-onboarding link hidden in demo.

Network:
- federation.list-nodes now returns 12 trusted/federated nodes (9 trusted, 3
  observer); transport.peers already at 5.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

neode-ui/src/views/appSession/appSessionConfig.ts

@@ -1,6 +1,7 @@
 /** Static configuration maps for app session routing and display */
 
 import { GENERATED_APP_PORTS, GENERATED_APP_TITLES, GENERATED_NEW_TAB_APPS } from './generatedAppSessionConfig'
+import { IS_DEMO, demoAppUrl } from '@/composables/useDemoIntro'
 
 export type DisplayMode = 'panel' | 'overlay' | 'fullscreen'
 
@@ -76,6 +77,12 @@ export const IFRAME_BLOCKED_APPS = new Set<string>([])
 
 /** Resolve app URL using direct port mapping (source of truth) */
 export function resolveAppUrl(id: string, routeQueryPath?: string, runtimeUrl?: string): string {
+  // Demo: route to the app's mock UI or real external site (mempool.space,
+  // indee.tx1138.com). Non-demoable apps fall through to a generic notice page.
+  if (IS_DEMO) {
+    return demoAppUrl(id) || `/app/${id}/`
+  }
+
   // External HTTPS apps
   const ext = EXTERNAL_URLS[id]
   if (ext) return ext