Merge main; keep inline panels polling while their host reports them hidden

Main now has #1282, which pauses periodic layer polling in a hidden page
with its own catch-up and listener cleanup, so this PR drops its duplicate
lifecycle.js change and test in favor of main's.

Review fixes:
- data.js passes panelAwareVisibility(document) (new in app/embed.js) as
  the lifecycle's visibility target, so an inline panel whose host reports
  it hidden keeps polling. The HUD's 250 ms readout follows the same
  document.hidden && !isEmbeddedInline() rule as tools.js.
- Tests: embed.test.mjs (layers poll in an inline panel reported hidden,
  pause without the flag) and hudPageVisibility.test.mjs (HUD readout).
  Both use mock timers and clean up in finally.
- changelog.d/1344-inline-panel-visibility.md and a note in
  docs/CURRENT-STATE.md.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/app/embed.test.mjs

@@ -5,7 +5,9 @@ import {
   installViews,
   isEmbedded,
   keepPanelRendering,
+  panelAwareVisibility,
 } from './embed.js';
+import { LayerLifecycle } from '../data/lifecycle.js';
 import { createView } from '../view/index.js';
 
 const fakeViewer = () => {
@@ -211,6 +213,60 @@ test('an app loaded inline into a panel page talks through its own window', asyn
   }
 });
 
+test('polled layers keep refreshing in an inline panel its host reports hidden', async (t) => {
+  const listeners = new Set();
+  const doc = {
+    hidden: true,
+    visibilityState: 'hidden',
+    addEventListener: (_type, fn) => listeners.add(fn),
+    removeEventListener: (_type, fn) => listeners.delete(fn),
+  };
+  const settle = async () => {
+    for (let i = 0; i < 3; i++) await Promise.resolve();
+  };
+  t.mock.timers.enable({ apis: ['setInterval', 'Date'], now: 1000 });
+  let updates = 0;
+  const manager = new LayerLifecycle(
+    {},
+    { visibilityTarget: panelAwareVisibility(doc) },
+  );
+  manager.register({
+    id: 'flights',
+    name: 'flights',
+    icon: '',
+    source: 'test',
+    updateInterval: 1000,
+    async init() {},
+    enable() {},
+    disable() {},
+    async update() {
+      updates++;
+      await Promise.resolve();
+    },
+    getStats: () => ({ count: 0, lastUpdate: null }),
+  });
+  globalThis.GEV_EMBED_INLINE = true;
+  try {
+    await manager.setEnabled('flights', true);
+    await settle();
+    const enabled = updates;
+    t.mock.timers.tick(1000);
+    await settle();
+    t.mock.timers.tick(1000);
+    await settle();
+    assert.equal(updates, enabled + 2, 'the panel keeps polling');
+
+    delete globalThis.GEV_EMBED_INLINE;
+    t.mock.timers.tick(1000);
+    await settle();
+    assert.equal(updates, enabled + 2, 'outside a panel a hidden page pauses');
+  } finally {
+    delete globalThis.GEV_EMBED_INLINE;
+    await manager.destroyAll();
+  }
+  assert.equal(listeners.size, 0);
+});
+
 test('annotations in a link are drawn after it restores, embedded or not', async () => {
   const { calls, run } = recorder();
   const an = encodeURIComponent(