fix(ui): first-login dashboard entrance restored + working Replay Intro

- playDashboardLoadOomph gated itself silent on the one entry that
  should be loud: onboarding is already flagged complete by the time the
  post-wizard dashboard mounts. force flag restores the full oomph there
  while keeping ordinary re-logins quiet (the intentional limit).
- OnboardingDone now hands Login a one-shot finale flag, so the login
  right after the wizard gets the full zoom + oomph even as a regular
  password login — which is exactly the demo flow (and TOTP logins).
- 'Replay intro' on the login screen actually replays: App.vue was
  instantly re-marking the intro as seen on onboarded nodes; an explicit
  one-shot replay flag now overrides every suppression rule (unit
  tested).

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

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

@@ -28,4 +28,14 @@ describe('shouldShowIntroSplash', () => {
       onboardingComplete: null,
     })).toBe(false)
   })
+
+  it('an explicit replay request overrides every suppression rule', () => {
+    expect(shouldShowIntroSplash({
+      seenIntro: true,
+      routePath: '/',
+      fromBoot: false,
+      onboardingComplete: true,
+      replayRequested: true,
+    })).toBe(true)
+  })
 })