Don't show "Get started" to someone who is signed in.

Boot decides whether a session restores, but plenty renders before it gets
there — the deferred feature chunks land and repaint, an emitter ticks — and
a render that early has no idea whether anyone is signed in. It painted the
welcome screen anyway, so a signed-in wallet flashed the sign-in page for the
~75ms before boot restored it. Waiting for the ark store widened the gap; the
race was already there.

The signed-out screen is now the one screen boot won't guess at: until the
session question is answered, the frame holds the boot shell (the brand row
it's already showing). Every other screen is a deliberate choice — a gift
claim, a locked vault, a chat — and still paints immediately. A release timer
makes sure a boot path that returns early can't hold it back for good.

tools/boot-signin-flash-test.js widens the race and checks every frame of
four reloads; before this it caught the flash on every one.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_019mrt228Upn9nNCwGixzSLx

1 files changed, 67 insertions, 0 deletions

diff --git a/tools/boot-signin-flash-test.js b/tools/boot-signin-flash-test.js
new file mode 100644
index 0000000..e46ee72
--- /dev/null
+++ b/tools/boot-signin-flash-test.js
@@ -0,0 +1,67 @@
+// A signed-in wallet must never flash the signed-out welcome screen. Anything
+// that renders before boot has restored the session (a deferred feature chunk
+// landing, an emitter tick) is rendering without knowing whether anyone is
+// signed in, and "Get started" over a wallet that's about to open is the one
+// wrong guess that's unmistakable.
+//
+// The race is widened here (the locale fetch is delayed, so the deferred
+// chunks land in the gap) and every animation frame of the boot is checked
+// for the welcome screen.
+//
+// Run: bun tools/boot-signin-flash-test.js
+import puppeteer from 'puppeteer-core';
+import { generateMnemonic } from '@scure/bip39';
+import { wordlist } from '@scure/bip39/wordlists/english';
+import { buildHtml } from '../build.js';
+const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
+const html = await buildHtml({ minify: true, pwa: false });
+const server = Bun.serve({ port: 5234, fetch: () => new Response(html, { headers: { 'content-type': 'text/html' } }) });
+const browser = await puppeteer.launch({ executablePath: '/usr/bin/google-chrome', headless: 'new', args: ['--no-sandbox'] });
+const page = await browser.newPage();
+const click = (t) => page.evaluate((x) => { const e = [...document.querySelectorAll('button')].find((n) => n.textContent.trim().toLowerCase().includes(x)); if (e) { e.click(); return true; } return false; }, t);
+const waitText = async (x, ms = 25000) => { for (let i = 0; i < ms / 250; i++) { if ((await page.evaluate(() => document.body.innerText)).toLowerCase().includes(x)) return true; await sleep(250); } return false; };
+let ok = true;
+try {
+  await page.setViewport({ width: 390, height: 844 });
+  await page.goto('http://localhost:5234/', { waitUntil: 'domcontentloaded' });
+  await page.evaluate(() => localStorage.setItem('btc-wallet-network', 'regtest'));
+  await page.reload({ waitUntil: 'domcontentloaded' });
+  await sleep(400);
+  await click('get started'); await sleep(500);
+  await click('import existing'); await sleep(400);
+  await page.waitForSelector('textarea');
+  await page.type('textarea', generateMnemonic(wordlist));
+  await click('open wallet');
+  await waitText('receive', 20000);
+
+  // Reload with the locale fetch held back, so whatever else renders during
+  // boot gets its chance, and watch every frame.
+  await page.evaluateOnNewDocument(() => {
+    const orig = window.fetch;
+    window.fetch = (...a) => {
+      const url = String(a[0] && a[0].url ? a[0].url : a[0]);
+      if (/locale|\.json$/i.test(url)) return sleepThen(600).then(() => orig(...a));
+      return orig(...a);
+    };
+    const sleepThen = (ms) => new Promise((r) => setTimeout(r, ms));
+    window.__frames = [];
+    window.__sawSignin = null;
+    const tick = () => {
+      const txt = (document.body && document.body.innerText) || '';
+      if (!window.__sawSignin && /get started|sign in with/i.test(txt)) window.__sawSignin = Math.round(performance.now());
+      if (!window.__walletAt && document.querySelector('.balance')) window.__walletAt = Math.round(performance.now());
+      if (!window.__walletAt) requestAnimationFrame(tick);
+    };
+    requestAnimationFrame(tick);
+  });
+  for (let i = 1; i <= 4; i++) {
+    await page.reload({ waitUntil: 'domcontentloaded' });
+    await sleep(3000);
+    const r = await page.evaluate(() => ({ signin: window.__sawSignin, wallet: window.__walletAt }));
+    const clean = r.signin == null && r.wallet != null;
+    console.log(` ${clean ? '✓' : '✗'} reload ${i}: wallet at ${r.wallet}ms${r.signin != null ? `, sign-in page flashed at ${r.signin}ms` : ', no sign-in flash'}`);
+    if (!clean) ok = false;
+  }
+} finally { await browser.close(); server.stop(true); }
+console.log(ok ? '\n✅ no sign-in flash' : '\n❌ the sign-in page flashed');
+process.exit(ok ? 0 : 1);