test: stabilize asynchronous UI checks in release CI

Control the native inventory retry response and wait for the complete
browser-close result instead of asserting on intermediate renders.
Run native note-layout input in a visible isolated Electron window,
scan the fixture dependencies up front, and report timeout explicitly.
Keep all behavior and geometry assertions and Electron sandboxing.

The three focused regressions, full typecheck, and lint pass locally.
Linux CI must confirm the release failures are resolved. No product,
Agent, version, or release-tag changes are included.

tests/magic-notes-layout.electron.test.ts

@@ -19,7 +19,8 @@ it('resizes record columns with native Electron input and preserves desktop widt
           '<html><body><script type="module" src="/tests/support/magic-notes-layout-regression.tsx"></script></body></html>'))
       })
     } }],
-    server: { host: '127.0.0.1', port: 0, watch: null }
+    server: { host: '127.0.0.1', port: 0, watch: null },
+    optimizeDeps: { entries: ['tests/support/magic-notes-layout-regression.tsx'] }
   })
   try {
     await server.listen()
@@ -31,7 +32,7 @@ it('resizes record columns with native Electron input and preserves desktop widt
       app.commandLine.appendSwitch('force-device-scale-factor', '1');
       app.setPath('userData', ${JSON.stringify(join(directory, 'profile'))});
       app.whenReady().then(async () => {
-        const win = new BrowserWindow({ show: false, width: 1280, height: 800, useContentSize: true,
+        const win = new BrowserWindow({ show: true, width: 1280, height: 800, useContentSize: true,
           webPreferences: { sandbox: true, contextIsolation: true, nodeIntegration: false, backgroundThrottling: false } });
         const js = code => win.webContents.executeJavaScript(code).catch(error => { throw new Error(code + ': ' + error.message); });
         const settle = () => js('new Promise(resolve => requestAnimationFrame(() => requestAnimationFrame(resolve)))');
@@ -165,10 +166,16 @@ it('resizes record columns with native Electron input and preserves desktop widt
     let output = ''
     child.stdout.on('data', data => { output += data })
     child.stderr.on('data', data => { output += data })
-    // Hidden Electron windows can run rAF at 1 Hz; the measured scenario takes 63s.
-    const timeout = setTimeout(() => child.kill(), 90000)
+    // Native input and animation frames need a visible window, including under Xvfb.
+    let timedOut = false
+    const timeout = setTimeout(() => { timedOut = true; child.kill() }, 90000)
     try {
-      const code = await new Promise((resolve, reject) => { child.once('exit', resolve); child.once('error', reject) })
+      const { code, signal } = await new Promise<{ code: number | null; signal: NodeJS.Signals | null }>((resolve, reject) => {
+        child.once('close', (code, signal) => resolve({ code, signal }))
+        child.once('error', reject)
+      })
+      expect(timedOut, `Electron layout exceeded 90s (exit=${code}, signal=${signal}).\n${output}`).toBe(false)
+      expect(signal, output).toBeNull()
       expect(code, output).toBe(0)
     } finally { clearTimeout(timeout) }
     const result = JSON.parse(await readFile(join(directory, 'result.json'), 'utf8'))