fix(ui): play the intro on backend-confirmed fresh nodes despite stale browser flags

neode_intro_seen / neode_onboarding_complete are per-origin browser state:
after a reinstall (or another node on a DHCP-recycled IP) they describe the
previous node and muted a genuinely fresh install's intro. Root boots now
always ask the backend; a confirmed-fresh answer plays the intro and clears
the stale flag.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

neode-ui/src/App.vue

@@ -424,10 +424,14 @@ onMounted(async () => {
   const { IS_DEMO } = await import('@/composables/useDemoIntro')
   if (IS_DEMO && bootPath === '/') replayRequested = true
   let onboardingComplete: boolean | null = localStorage.getItem('neode_onboarding_complete') === '1' ? true : null
-  const splashCandidate = !seenIntro
-    && (fromBoot || (bootPath === '/' && import.meta.env.VITE_DEV_MODE !== 'boot'))
+  // Root boots always ask the backend — even when this browser thinks it has
+  // seen the intro. Both `neode_intro_seen` and `neode_onboarding_complete`
+  // are per-origin browser state: after a reinstall (or another node coming
+  // up on a DHCP-recycled IP) they describe the PREVIOUS node and would mute
+  // a fresh install's intro / misroute it to login.
+  const splashCandidate = fromBoot || (bootPath === '/' && import.meta.env.VITE_DEV_MODE !== 'boot')
 
-  if (splashCandidate && onboardingComplete !== true) {
+  if (splashCandidate) {
     try {
       const { checkOnboardingStatus } = await import('@/composables/useOnboarding')
       // Bound the pre-splash status check: its retry ladder can spend ~30s
@@ -437,10 +441,17 @@ onMounted(async () => {
       // the splash play (a fresh install IS the slow-backend case; onboarded
       // nodes answer in milliseconds, so their suppression path is intact).
       // handleSplashComplete re-checks with full retries after the intro.
-      onboardingComplete = await Promise.race([
+      const live = await Promise.race([
         checkOnboardingStatus(),
         new Promise<null>((resolve) => setTimeout(() => resolve(null), 2500)),
       ])
+      if (live !== null) onboardingComplete = live
+      if (live === false && seenIntro) {
+        // Backend-confirmed fresh node behind a browser with a stale flag —
+        // drop it so this boot (and every later one) plays the intro.
+        try { localStorage.removeItem('neode_intro_seen') } catch { /* noop */ }
+        seenIntro = false
+      }
     } catch {
       onboardingComplete = localStorage.getItem('neode_onboarding_complete') === '1' ? true : null
     }

neode-ui/src/utils/__tests__/introSplash.test.ts

@@ -38,4 +38,50 @@ describe('shouldShowIntroSplash', () => {
       replayRequested: true,
     })).toBe(true)
   })
+
+  it('a confirmed-fresh node plays the intro despite a stale per-origin seenIntro flag (reinstall / DHCP-recycled IP)', () => {
+    expect(shouldShowIntroSplash({
+      seenIntro: true,
+      routePath: '/',
+      fromBoot: false,
+      onboardingComplete: false,
+    })).toBe(true)
+  })
+
+  it('a confirmed-fresh node plays the intro on the boot-screen handoff too', () => {
+    expect(shouldShowIntroSplash({
+      seenIntro: true,
+      routePath: '/login',
+      fromBoot: true,
+      onboardingComplete: false,
+    })).toBe(true)
+  })
+
+  it('stale seenIntro still suppresses when the backend answer is unknown', () => {
+    expect(shouldShowIntroSplash({
+      seenIntro: true,
+      routePath: '/',
+      fromBoot: false,
+      onboardingComplete: null,
+    })).toBe(false)
+  })
+
+  it('fresh node on a deep route without boot handoff stays suppressed', () => {
+    expect(shouldShowIntroSplash({
+      seenIntro: false,
+      routePath: '/onboarding/seed',
+      fromBoot: false,
+      onboardingComplete: false,
+    })).toBe(false)
+  })
+
+  it('boot dev mode never root-boots into the intro', () => {
+    expect(shouldShowIntroSplash({
+      seenIntro: false,
+      routePath: '/',
+      fromBoot: false,
+      devMode: 'boot',
+      onboardingComplete: false,
+    })).toBe(false)
+  })
 })

neode-ui/src/utils/introSplash.ts

@@ -10,10 +10,19 @@ export interface IntroSplashDecisionInput {
 
 export function shouldShowIntroSplash(input: IntroSplashDecisionInput): boolean {
   if (input.replayRequested) return true
+
+  const isDirectRoute = input.routePath !== '/'
+  // A node the backend CONFIRMS has never completed onboarding always gets
+  // the full intro on a root boot. `seenIntro` is per-origin browser state —
+  // after a reinstall (or a DHCP-recycled IP), the browser still carries the
+  // previous node's flag at the same origin, which silently muted the intro
+  // on genuinely fresh installs.
+  if (input.onboardingComplete === false && (input.fromBoot || (!isDirectRoute && input.devMode !== 'boot'))) {
+    return true
+  }
   if (input.seenIntro) return false
   if (input.onboardingComplete === true) return false
 
-  const isDirectRoute = input.routePath !== '/'
   if (input.fromBoot) return true
   if (input.devMode === 'boot') return false
   return !isDirectRoute