From 657fd589d7c30c41b111b1e46351b20c92a50c49 Mon Sep 17 00:00:00 2001
From: knotty <sarmstrong1@gmail.com>
Date: Mon, 19 Oct 2026 10:30:17 -0600
Subject: [PATCH 01/10] test(terrain): give every terrain-heights proxy in the
 bounds tests its own cache

Seven tests built terrainHeightsProxy() with no cachePath, so the proxy fell
back to this checkout's .gev-cache/terrain-heights.json. A point the app had
already cached there answered a request the test expected to reach the
stubbed upstream: after running the dev server near Austin, the cross-site
test failed with 1 !== 2.

isolatedCachePath(t) gives each test a mkdtemp cache file removed in
t.after, as the over-large cache test already did; that test now uses it too.

Fixes #1242.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BNTtHAa65nobzJ7jp2Ltr4
---
 src/terrainHeightsBounds.test.mjs | 49 +++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 12 deletions(-)

diff --git a/src/terrainHeightsBounds.test.mjs b/src/terrainHeightsBounds.test.mjs
index cd1a9ad36..88b26b694 100644
--- a/src/terrainHeightsBounds.test.mjs
+++ b/src/terrainHeightsBounds.test.mjs
@@ -99,6 +99,18 @@ function stubTerrainUpstream(t) {
   return asked;
 }
 
+/**
+ * A cache file of the test's own, removed when the test ends. Without one the
+ * proxy falls back to this checkout's `.gev-cache/terrain-heights.json`, and a
+ * point the app has already cached there would answer a request the test
+ * expects to reach the stubbed upstream (#1242).
+ */
+async function isolatedCachePath(t) {
+  const dir = await mkdtemp(path.join(tmpdir(), 'gev-terrain-'));
+  t.after(() => rm(dir, { recursive: true, force: true }));
+  return path.join(dir, 'terrain-heights.json');
+}
+
 test('a coordinate off the globe is not a cache key', () => {
   // Finite but not on Earth — the old guard accepted every one of these.
   for (const raw of [
@@ -122,7 +134,9 @@ test('an out-of-range point is refused before it reaches upstream or the cache',
     upstreamCalls += 1;
     return new Response('[]', { status: 200 });
   });
-  const route = install(terrainHeightsProxy()).get('/api/terrain/heights');
+  const route = install(
+    terrainHeightsProxy({ cachePath: await isolatedCachePath(t) }),
+  ).get('/api/terrain/heights');
 
   const refused = await request(route, { url: '/?points=0,91' });
   assert.equal(refused.statusCode, 400);
@@ -135,7 +149,9 @@ test('an out-of-range point is refused before it reaches upstream or the cache',
 
 test('one out-of-range point rejects the batch it is hidden in', async (t) => {
   stubFetch(t, async () => new Response('[]', { status: 200 }));
-  const route = install(terrainHeightsProxy()).get('/api/terrain/heights');
+  const route = install(
+    terrainHeightsProxy({ cachePath: await isolatedCachePath(t) }),
+  ).get('/api/terrain/heights');
   const mixed = await request(route, {
     url: '/?points=-97.74,30.26;0,999;-97.75,30.27',
   });
@@ -145,9 +161,12 @@ test('one out-of-range point rejects the batch it is hidden in', async (t) => {
 test('the point cache stops growing, and an evicted point is simply refetched', async (t) => {
   const asked = stubTerrainUpstream(t);
   // A ceiling of 3 exercises the same code path 50,000 does, in four requests.
-  const route = install(terrainHeightsProxy({ cacheMaxEntries: 3 })).get(
-    '/api/terrain/heights',
-  );
+  const route = install(
+    terrainHeightsProxy({
+      cachePath: await isolatedCachePath(t),
+      cacheMaxEntries: 3,
+    }),
+  ).get('/api/terrain/heights');
 
   const point = (i) => `-97.7${i}000,30.26000`;
   for (let i = 1; i <= 4; i += 1)
@@ -168,9 +187,7 @@ test('the point cache stops growing, and an evicted point is simply refetched',
 test('an over-large cache file is not read back into memory', async (t) => {
   const asked = stubTerrainUpstream(t);
   const point = '-97.74000,30.26000';
-  const dir = await mkdtemp(path.join(tmpdir(), 'gev-terrain-'));
-  const cachePath = path.join(dir, 'terrain-heights.json');
-  t.after(() => rm(dir, { recursive: true, force: true }));
+  const cachePath = await isolatedCachePath(t);
 
   // A cache file holding the answer, but larger than the ceiling allows.
   const padded = {
@@ -201,7 +218,9 @@ test('an over-large cache file is not read back into memory', async (t) => {
 
 test('the route refuses a flood of requests from one client', async (t) => {
   stubTerrainUpstream(t);
-  const route = install(terrainHeightsProxy()).get('/api/terrain/heights');
+  const route = install(
+    terrainHeightsProxy({ cachePath: await isolatedCachePath(t) }),
+  ).get('/api/terrain/heights');
 
   let refusedAt = 0;
   for (let i = 1; i <= 95; i += 1) {
@@ -218,7 +237,9 @@ test('the route refuses a flood of requests from one client', async (t) => {
 
 test('a cross-site page cannot fill the cache or spend the visitor quota', async (t) => {
   const asked = stubTerrainUpstream(t);
-  const route = install(terrainHeightsProxy()).get('/api/terrain/heights');
+  const route = install(
+    terrainHeightsProxy({ cachePath: await isolatedCachePath(t) }),
+  ).get('/api/terrain/heights');
   const host = 'localhost:5173';
   const refused = [
     { host, 'sec-fetch-site': 'cross-site' }, // <img src> from any web page
@@ -253,7 +274,9 @@ test('a cross-site page cannot fill the cache or spend the visitor quota', async
 
 test('the app served behind a reverse proxy still gets terrain', async (t) => {
   const asked = stubTerrainUpstream(t);
-  const route = install(terrainHeightsProxy()).get('/api/terrain/heights');
+  const route = install(
+    terrainHeightsProxy({ cachePath: await isolatedCachePath(t) }),
+  ).get('/api/terrain/heights');
   const host = 'globe.example.lan';
   // What nginx/Caddy/Cloudflare add in front of a same-origin app fetch. The
   // cost-bearing routes refuse these; terrain is keyless and needed to render,
@@ -347,7 +370,9 @@ test('a second client keeps its own quota', async (t) => {
   stubFetch(t, async () =>
     Response.json([{ lng: -97.74, lat: 30.26, height: 150 }]),
   );
-  const route = install(terrainHeightsProxy()).get('/api/terrain/heights');
+  const route = install(
+    terrainHeightsProxy({ cachePath: await isolatedCachePath(t) }),
+  ).get('/api/terrain/heights');
 
   for (let i = 0; i < 90; i += 1)
     await request(route, {

From 6bb2856403b382eb0befacd5568565589967dede Mon Sep 17 00:00:00 2001
From: knotty <sarmstrong1@gmail.com>
Date: Mon, 19 Oct 2026 10:30:41 -0600
Subject: [PATCH 02/10] docs(changelog): add the terrain test cache isolation
 fragment

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BNTtHAa65nobzJ7jp2Ltr4
---
 changelog.d/1244-terrain-test-cache-isolation.md | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 changelog.d/1244-terrain-test-cache-isolation.md

diff --git a/changelog.d/1244-terrain-test-cache-isolation.md b/changelog.d/1244-terrain-test-cache-isolation.md
new file mode 100644
index 000000000..5efacd3bb
--- /dev/null
+++ b/changelog.d/1244-terrain-test-cache-isolation.md
@@ -0,0 +1,4 @@
+- The terrain-heights bounds tests no longer read the checkout's
+  `.gev-cache/terrain-heights.json`. Each test gets a cache file of its own, so
+  `npm test` no longer fails after the dev server has cached terrain near
+  Austin (KnottyDyes, #1244).

From ec0985618c5697776ef9ed1402e868d5e00719cc Mon Sep 17 00:00:00 2001
From: Said <asturksever@mac.home>
Date: Tue, 20 Oct 2026 01:25:40 +0100
Subject: [PATCH 03/10] fix(layers): pause periodic network updates in hidden
 tabs

---
 docs/CURRENT-STATE.md           |  2 ++
 src/app/data.js                 |  1 +
 src/data/lifecycle.js           | 57 +++++++++++++++++++++++----------
 src/data/manager.js             |  2 +-
 src/data/manager.test.mjs       | 31 ++++++++++++++++++
 src/layers/transit/lifecycle.js |  1 +
 src/layers/transit/viewport.js  |  5 +++
 7 files changed, 81 insertions(+), 18 deletions(-)

diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index 55b7a63ab..508b6264d 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -1,5 +1,7 @@
 # God's Eye View Current State
 
+Manager-owned periodic network updates pause while the document is hidden. Returning to a visible tab runs one overdue update per enabled layer without overlapping an active refresh; explicit refresh requests remain available. Transit also defers camera-driven feed admission while hidden and rechecks coverage on return. Visibility listeners are released with their polling intervals.
+
 Shared distance checks use `src/geoDistance.js` with `{ lat, lon }` points and
 the IUGG mean spherical Earth radius, 6371.0088 km. `greatCircleKm` is
 canonical; `greatCircleMeters` is its exact metre conversion. Missing,
diff --git a/src/app/data.js b/src/app/data.js
index ce3ad0731..e6c7d25e0 100644
--- a/src/app/data.js
+++ b/src/app/data.js
@@ -13,6 +13,7 @@ export function createApplicationData({
   // Initialize data layer manager
   const dataManager = new LayerLifecycle(viewer, {
     allowQaRegistration,
+    visibilityTarget: document,
     getSourceAvailability: catalog?.getSourceAvailability,
   });
   defer(async () => {
diff --git a/src/data/lifecycle.js b/src/data/lifecycle.js
index 0df5e87a4..01aaf6124 100644
--- a/src/data/lifecycle.js
+++ b/src/data/lifecycle.js
@@ -72,13 +72,20 @@ function refreshFailureFromStats(stats, label) {
 /**
  * LayerLifecycle — Manages registration, toggling, and update loops
  * for real-time data overlays on the CesiumJS globe.
+ * Hosts may inject a visibilityTarget with hidden/visibilityState and event
+ * listener methods. Without one, periodic work retains its headless behavior.
  */
 export class LayerLifecycle {
   constructor(
     viewer,
-    { allowQaRegistration = false, getSourceAvailability } = {},
+    {
+      allowQaRegistration = false,
+      getSourceAvailability,
+      visibilityTarget = null,
+    } = {},
   ) {
     this._catalogSourceAvailability = getSourceAvailability;
+    this._visibilityTarget = visibilityTarget;
     this.viewer = viewer;
     this._activityListeners = new Set();
     this.layers = new Map(); // id → { module, enabled, initialized, intervalId, lifecycleState, lifecycleUncertain }
@@ -528,6 +535,13 @@ export class LayerLifecycle {
     }
   }
 
+  _stopUpdateLoop(entry) {
+    clearInterval(entry.intervalId);
+    entry.intervalId = null;
+    entry.removeVisibilityListener?.();
+    entry.removeVisibilityListener = null;
+  }
+
   _armUpdateLoop(layerId, entry) {
     const configuredRefreshInterval = Number(entry.module.refreshInterval);
     const updateInterval = Number(entry.module.updateInterval);
@@ -538,9 +552,25 @@ export class LayerLifecycle {
           ? updateInterval
           : 0;
     if (refreshInterval > 0) {
-      entry.intervalId = setInterval(() => {
+      const visibilityDocument = this._visibilityTarget;
+      let dueAt = Date.now() + refreshInterval;
+      const tick = () => {
+        if (
+          visibilityDocument?.hidden ||
+          visibilityDocument?.visibilityState === 'hidden' ||
+          !entry.enabled ||
+          entry.destroying ||
+          entry.refreshing ||
+          Date.now() < dueAt
+        )
+          return;
+        dueAt = Date.now() + refreshInterval;
         void this._runPeriodicUpdate(layerId, entry);
-      }, refreshInterval);
+      };
+      entry.intervalId = setInterval(tick, refreshInterval);
+      visibilityDocument?.addEventListener?.('visibilitychange', tick);
+      entry.removeVisibilityListener = () =>
+        visibilityDocument?.removeEventListener?.('visibilitychange', tick);
     } else if (updateInterval === 0) {
       entry.intervalId = setInterval(() => {
         if (!entry.enabled) return;
@@ -772,8 +802,7 @@ export class LayerLifecycle {
         entry.lifecycleUncertain = !compensated && !cleanupConfirmed;
         settleLifecycle();
         if (!entry.enabled && entry.intervalId) {
-          clearInterval(entry.intervalId);
-          entry.intervalId = null;
+          this._stopUpdateLoop(entry);
         }
         this._publishActivity({ type: 'status' });
         if (!compensated) {
@@ -833,8 +862,7 @@ export class LayerLifecycle {
       }
       if (signal?.aborted) return finishCancelledDisable('disable');
       if (entry.intervalId) {
-        clearInterval(entry.intervalId);
-        entry.intervalId = null;
+        this._stopUpdateLoop(entry);
       }
       entry.enabled = false;
       entry.lifecycleUncertain = false;
@@ -845,8 +873,7 @@ export class LayerLifecycle {
       let abortCleanup = null;
       const cancelEnable = () => {
         if (entry.intervalId) {
-          clearInterval(entry.intervalId);
-          entry.intervalId = null;
+          this._stopUpdateLoop(entry);
         }
         // Disable immediately so modules with their own AbortController (Radio)
         // cancel pending update work at the same turn boundary. A second
@@ -876,8 +903,7 @@ export class LayerLifecycle {
         // a later abort cannot revoke a successful retry.
         signal?.removeEventListener('abort', cancelEnable);
         if (entry.intervalId) {
-          clearInterval(entry.intervalId);
-          entry.intervalId = null;
+          this._stopUpdateLoop(entry);
         }
         await abortCleanup;
         let cleanupConfirmed = false;
@@ -918,8 +944,7 @@ export class LayerLifecycle {
       };
       const finishFailedEnable = async (phase, error) => {
         if (entry.intervalId) {
-          clearInterval(entry.intervalId);
-          entry.intervalId = null;
+          this._stopUpdateLoop(entry);
         }
         let cleanupConfirmed = false;
         try {
@@ -1029,8 +1054,7 @@ export class LayerLifecycle {
       // Always clear any stale interval before assigning a new one, so we never
       // orphan a running timer and end up double-polling.
       if (entry.intervalId) {
-        clearInterval(entry.intervalId);
-        entry.intervalId = null;
+        this._stopUpdateLoop(entry);
       }
 
       // Manager-owned periodic refresh work has one normalized loading/error
@@ -2158,8 +2182,7 @@ export class LayerLifecycle {
         return false;
       }
       if (entry.intervalId) {
-        clearInterval(entry.intervalId);
-        entry.intervalId = null;
+        this._stopUpdateLoop(entry);
       }
       entry.enabled = false;
     }
diff --git a/src/data/manager.js b/src/data/manager.js
index b719b5934..79bb7d9ae 100644
--- a/src/data/manager.js
+++ b/src/data/manager.js
@@ -5,7 +5,7 @@ export { layerFeedState } from '../ui/layers.js';
 /** Compatibility facade for callers that construct a manager with its panel. */
 export class DataLayerManager extends LayerLifecycle {
   constructor(viewer, options) {
-    super(viewer, options);
+    super(viewer, { visibilityTarget: globalThis.document, ...options });
     this._presentation = new LayerPresentation(this);
   }
   buildTogglePanel(container) {
diff --git a/src/data/manager.test.mjs b/src/data/manager.test.mjs
index 23641c962..68a0644f1 100644
--- a/src/data/manager.test.mjs
+++ b/src/data/manager.test.mjs
@@ -3492,3 +3492,34 @@ test('refreshLayerStats reaches presentation through the bare lifecycle', async
   lifecycle.refreshLayerStats();
   assert.deepEqual(changes, ['status']);
 });
+
+test('periodic polls pause hidden, catch up once when due, and dispose visibility listeners', async (t) => {
+  const listeners = new Set();
+  const doc = {
+    hidden: false,
+    addEventListener: (_name, fn) => listeners.add(fn),
+    removeEventListener: (_name, fn) => listeners.delete(fn),
+  };
+  t.mock.timers.enable({ apis: ['setInterval', 'Date'], now: 1000 });
+  const { LayerLifecycle } = await import('./lifecycle.js');
+  const manager = new LayerLifecycle({}, { visibilityTarget: doc });
+  const { module, calls } = makeSlowLayer('hidden-poll');
+  manager.register(module);
+  await manager.setEnabled('hidden-poll', true);
+  assert.equal(calls.update, 1);
+  doc.hidden = true;
+  t.mock.timers.tick(10000);
+  assert.equal(calls.update, 1);
+  assert.equal(await manager.refreshLayer('hidden-poll'), true);
+  assert.equal(calls.update, 2, 'explicit refresh remains allowed');
+  doc.hidden = false;
+  for (const fn of listeners) fn();
+  for (const fn of listeners) fn();
+  assert.equal(calls.update, 3);
+  await Promise.resolve();
+  await Promise.resolve();
+  await manager.destroyAll();
+  assert.equal(listeners.size, 0);
+  t.mock.timers.tick(10000);
+  assert.equal(calls.update, 3);
+});
diff --git a/src/layers/transit/lifecycle.js b/src/layers/transit/lifecycle.js
index 11b670519..90210063a 100644
--- a/src/layers/transit/lifecycle.js
+++ b/src/layers/transit/lifecycle.js
@@ -97,6 +97,7 @@ export function createLifecycle({ state, services, parts }) {
     else if (hidden) {
       hidden = false;
       parts.rendering.resumePlayback();
+      parts.viewport.runProximityCheck();
     }
   }
   function bindVisibility() {
diff --git a/src/layers/transit/viewport.js b/src/layers/transit/viewport.js
index 641fab5a2..730126f10 100644
--- a/src/layers/transit/viewport.js
+++ b/src/layers/transit/viewport.js
@@ -75,6 +75,11 @@ export function createViewport({ state, services, parts }) {
   }
 
   function runProximityCheck() {
+    if (
+      globalThis.document?.hidden ||
+      globalThis.document?.visibilityState === 'hidden'
+    )
+      return;
     if (!state._enabled || !state._viewer) return;
     refreshViewBounds();
     const altitude = getCameraAltitude();

From eabff9005d894454b22a66144a0582fe195aa3e7 Mon Sep 17 00:00:00 2001
From: Said <asturksever@mac.home>
Date: Tue, 20 Oct 2026 01:26:21 +0100
Subject: [PATCH 04/10] docs: record polling fix

---
 changelog.d/1282-polling-issue-fix.md | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/1282-polling-issue-fix.md

diff --git a/changelog.d/1282-polling-issue-fix.md b/changelog.d/1282-polling-issue-fix.md
new file mode 100644
index 000000000..82f9a0fba
--- /dev/null
+++ b/changelog.d/1282-polling-issue-fix.md
@@ -0,0 +1 @@
+- Pause periodic network updates in hidden tabs (asturksever, #1282).

From e4955f351ff8c7068748b22e9673e7b61edd7d92 Mon Sep 17 00:00:00 2001
From: Said <asturksever@Saids-MacBook-Air.local>
Date: Tue, 20 Oct 2026 14:07:13 +0100
Subject: [PATCH 05/10] test: qualify Transit visibility and city feed
 ownership

---
 changelog.d/1282-polling-issue-fix.md |  2 ++
 scripts/qa-transit-browser.mjs        |  5 ++++
 scripts/qa-transit-controls.mjs       |  5 ++++
 scripts/qa-transit.mjs                | 42 ++++++++++++++++++++-------
 src/tooling/transitQa.test.mjs        | 13 +++++++++
 5 files changed, 57 insertions(+), 10 deletions(-)

diff --git a/changelog.d/1282-polling-issue-fix.md b/changelog.d/1282-polling-issue-fix.md
index 82f9a0fba..c7b0dec0a 100644
--- a/changelog.d/1282-polling-issue-fix.md
+++ b/changelog.d/1282-polling-issue-fix.md
@@ -1 +1,3 @@
 - Pause periodic network updates in hidden tabs (asturksever, #1282).
+- Report and guard browser visibility during Transit QA so hidden-page polling pauses cannot masquerade as playback regressions (asturksever, #1282).
+- Require each live city to supply its own feed vehicles in Transit QA; retained vehicles cannot qualify another city (asturksever, #1282).
diff --git a/scripts/qa-transit-browser.mjs b/scripts/qa-transit-browser.mjs
index eb7b59985..23925c743 100644
--- a/scripts/qa-transit-browser.mjs
+++ b/scripts/qa-transit-browser.mjs
@@ -47,6 +47,7 @@ export async function reportTransitVisibility(page, label) {
     const layer = app.dataManager.layers.get('transit').module;
     const state = layer._transitStateForTest();
     return {
+      pageVisibility: document.visibilityState,
       total: state._vehicles.size,
       visible: state._visible.size,
       moving: state._moving.size,
@@ -59,6 +60,10 @@ export async function reportTransitVisibility(page, label) {
     };
   });
   console.log(`  ${label}: ${JSON.stringify(result)}`);
+  if (result.pageVisibility !== 'visible')
+    throw new Error(
+      `${label}: Transit QA requires a visible page; hidden pages deliberately pause polling`,
+    );
   if (result.renderLoop === false || result.renderErrors.length)
     throw new Error(
       `${label}: Cesium render loop stopped or raised an error: ${JSON.stringify(result.renderErrors)}`,
diff --git a/scripts/qa-transit-controls.mjs b/scripts/qa-transit-controls.mjs
index b76e14706..70ed1503c 100644
--- a/scripts/qa-transit-controls.mjs
+++ b/scripts/qa-transit-controls.mjs
@@ -1,6 +1,7 @@
 const pause = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
 export const BOSTON = {
   id: 'boston',
+  feedId: 'mbta',
   label: 'Boston (MBTA)',
   lat: 42.3554,
   lon: -71.0605,
@@ -11,6 +12,7 @@ const LIVE_CITIES = [
   BOSTON,
   {
     id: 'austin',
+    feedId: 'capmetro-austin',
     label: 'Austin (CapMetro)',
     lat: 30.2672,
     lon: -97.7431,
@@ -19,6 +21,7 @@ const LIVE_CITIES = [
   },
   {
     id: 'minneapolis',
+    feedId: 'metrotransit-msp',
     label: 'Minneapolis (Metro Transit)',
     lat: 44.9778,
     lon: -93.265,
@@ -27,6 +30,7 @@ const LIVE_CITIES = [
   },
   {
     id: 'helsinki',
+    feedId: 'hsl-helsinki',
     label: 'Helsinki (HSL)',
     lat: 60.1699,
     lon: 24.9384,
@@ -35,6 +39,7 @@ const LIVE_CITIES = [
   },
   {
     id: 'oslo',
+    feedId: 'entur-norway',
     label: 'Oslo (Entur)',
     lat: 59.9139,
     lon: 10.7522,
diff --git a/scripts/qa-transit.mjs b/scripts/qa-transit.mjs
index 7d83d77a4..fb0c66098 100644
--- a/scripts/qa-transit.mjs
+++ b/scripts/qa-transit.mjs
@@ -266,6 +266,7 @@ const browser = await puppeteer.launch({
   executablePath: chromeExecutablePath(),
   args: [
     '--no-sandbox',
+    '--disable-backgrounding-occluded-windows',
     '--disable-background-timer-throttling',
     '--disable-renderer-backgrounding',
     '--window-size=1920,1080',
@@ -391,22 +392,42 @@ try {
         orientation: { heading: 0, pitch: (-40 * Math.PI) / 180, roll: 0 },
       });
     }, city);
-    await page.waitForFunction(
-      () =>
-        (window.__godsEyeView.dataManager.layers
-          .get('transit')
-          .module.getStats().count || 0) > 0,
-      { timeout: 90_000 },
-    );
+    const arrived = await page
+      .waitForFunction(
+        (feedId) =>
+          [
+            ...window.__godsEyeView.dataManager.layers
+              .get('transit')
+              .module._transitStateForTest()
+              ._vehicles.keys(),
+          ].some((key) => key.startsWith(`${feedId}:`)),
+        { timeout: 90_000 },
+        city.feedId,
+      )
+      .then(
+        () => true,
+        () => false,
+      );
+    if (!arrived) {
+      check(
+        `${city.label}: live feed arrived`,
+        false,
+        `No vehicles from ${city.feedId}; retained vehicles from other cities cannot qualify this view`,
+        { unexercised: true },
+      );
+      continue;
+    }
     await wait(9_000);
-    const fleet = await page.evaluate(() => {
+    const fleet = await page.evaluate((feedId) => {
       const layer =
         window.__godsEyeView.dataManager.layers.get('transit').module;
       return {
-        count: layer._transitStateForTest()._vehicles.size,
+        count: [...layer._transitStateForTest()._vehicles.keys()].filter(
+          (key) => key.startsWith(`${feedId}:`),
+        ).length,
         stats: layer.getStats(),
       };
-    });
+    }, city.feedId);
     check(
       `${city.label}: vehicles are rendered`,
       fleet.count >= 20,
@@ -428,6 +449,7 @@ try {
         .module._transitStateForTest();
       let best = null;
       for (const entry of state._vehicles.values()) {
+        if (!entry.key.startsWith(`${c.feedId}:`)) continue;
         const d = Math.hypot(entry.to.lat - c.lat, entry.to.lon - c.lon);
         if (!best || d < best.d)
           best = { d, lat: entry.to.lat, lon: entry.to.lon, key: entry.key };
diff --git a/src/tooling/transitQa.test.mjs b/src/tooling/transitQa.test.mjs
index 51e4d5c44..634538c2a 100644
--- a/src/tooling/transitQa.test.mjs
+++ b/src/tooling/transitQa.test.mjs
@@ -1,6 +1,7 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 import { readFileSync } from 'node:fs';
+import { getTransitFeed } from '../data/transitFeeds.js';
 import {
   chooseLiveCities,
   selectStyle,
@@ -101,6 +102,18 @@ test('live visual cities follow local operating hours in summer and winter', ()
     const cities = chooseLiveCities(now);
     assert.ok(cities.length >= 1);
     for (const city of cities) {
+      const feed = getTransitFeed(city.feedId);
+      assert.ok(feed, `${city.id} has a registered feed`);
+      const distanceKm =
+        111.32 *
+        Math.hypot(
+          feed.center.lat - city.lat,
+          (feed.center.lon - city.lon) * Math.cos((city.lat * Math.PI) / 180),
+        );
+      assert.ok(
+        distanceKm < feed.loadRadiusKm,
+        `${city.id} is inside its feed's admission region`,
+      );
       const local = Number(
         new Intl.DateTimeFormat('en', {
           timeZone: city.zone,

From 2c8b3593d1af5ae2291c178f9105da0a01060223 Mon Sep 17 00:00:00 2001
From: Said <asturksever@Saids-MacBook-Air.local>
Date: Tue, 20 Oct 2026 14:19:11 +0100
Subject: [PATCH 06/10] test: observe a poll transition in the Transit anchor
 probe

---
 changelog.d/1282-polling-issue-fix.md |  1 +
 scripts/qa-transit.mjs                | 27 +++++++++++++++++++++++----
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/changelog.d/1282-polling-issue-fix.md b/changelog.d/1282-polling-issue-fix.md
index c7b0dec0a..f3aede4e4 100644
--- a/changelog.d/1282-polling-issue-fix.md
+++ b/changelog.d/1282-polling-issue-fix.md
@@ -1,3 +1,4 @@
 - Pause periodic network updates in hidden tabs (asturksever, #1282).
 - Report and guard browser visibility during Transit QA so hidden-page polling pauses cannot masquerade as playback regressions (asturksever, #1282).
 - Require each live city to supply its own feed vehicles in Transit QA; retained vehicles cannot qualify another city (asturksever, #1282).
+- Bound the Transit card-anchor probe by observed poll coverage instead of a fixed 20-second window (asturksever, #1282).
diff --git a/scripts/qa-transit.mjs b/scripts/qa-transit.mjs
index fb0c66098..628983e74 100644
--- a/scripts/qa-transit.mjs
+++ b/scripts/qa-transit.mjs
@@ -40,6 +40,7 @@ import { chromeExecutablePath } from './qa-chrome.mjs';
 import { createTransitHistory } from '../server/providers/transitHistory.js';
 import { DETECTION_THEME_MAP } from '../src/overlays/worldOverlayTokens.js';
 import { transitModeTier } from '../src/data/transitPresetStyle.js';
+import { TRANSIT_POLL_MS } from '../src/layers/transit/policy.js';
 
 import {
   reduceAnchor,
@@ -1631,6 +1632,7 @@ try {
             m[3] * v[0] + m[7] * v[1] + m[11] * v[2] + m[15] * v[3],
           ];
           const frames = [];
+          const observedPolls = new Set();
           const publicationsBefore = state._cardPublications || 0;
           let headSamples = 0,
             headErrorPx = 0,
@@ -1647,6 +1649,13 @@ try {
                 const proj = scene.camera.frustum.projectionMatrix;
                 const p = entry.marker.position;
                 const clip = mul(proj, mul(view, [p.x, p.y, p.z, 1]));
+                if (
+                  entry.marker.show !== false &&
+                  rect &&
+                  Number.isFinite(entry.pollSeq)
+                ) {
+                  observedPolls.add(entry.pollSeq);
+                }
                 frames.push({
                   t: performance.now() - t0,
                   mx: ((clip[0] / clip[3]) * 0.5 + 0.5) * canvas.clientWidth,
@@ -1692,7 +1701,15 @@ try {
                   headSamples++;
                 }
               }
-              if (performance.now() - t0 >= durationMs) finish();
+              const elapsed = performance.now() - t0;
+              // Keep at least 20 seconds of motion and require an observed poll
+              // transition. A fixed 20s wall-clock window can miss a 15s poll
+              // when an earlier refresh is still settling.
+              if (
+                (elapsed >= 20_000 && observedPolls.size >= 2) ||
+                elapsed >= durationMs
+              )
+                finish();
             };
             let remove;
             const finish = () => {
@@ -1700,6 +1717,7 @@ try {
               remove?.();
               resolve({
                 selected: true,
+                elapsedMs: performance.now() - t0,
                 frames,
                 textPublishes:
                   (state._cardPublications || 0) - publicationsBefore,
@@ -1714,7 +1732,7 @@ try {
           });
         },
         target.key,
-        20_000,
+        3 * TRANSIT_POLL_MS,
       );
     }
     check(
@@ -1735,8 +1753,9 @@ try {
       );
       check(
         'card text publication stays throttled while the anchor runs at frame rate',
-        anchor.textPublishes > 0 && anchor.textPublishes <= 20_000 / 250 + 3,
-        `${anchor.textPublishes} text publications in 20 s`,
+        anchor.textPublishes > 0 &&
+          anchor.textPublishes <= anchor.elapsedMs / 250 + 3,
+        `${anchor.textPublishes} text publications in ${(anchor.elapsedMs / 1000).toFixed(1)} s`,
       );
     } else {
       check(

From 5b9c726f33e7eb6e9af400f981f42ae2ef243628 Mon Sep 17 00:00:00 2001
From: Said <asturksever@Saids-MacBook-Air.local>
Date: Tue, 20 Oct 2026 14:37:57 +0100
Subject: [PATCH 07/10] test: prove hidden-tab polling in a real browser

---
 changelog.d/1282-polling-issue-fix.md |   2 +
 docs/CURRENT-STATE.md                 |   2 +
 scripts/format-scope.json             |   3 +-
 scripts/qa-layer-visibility.mjs       | 124 ++++++++++++++++++++++++++
 scripts/qa-transit.mjs                |   4 +
 5 files changed, 134 insertions(+), 1 deletion(-)
 create mode 100644 scripts/qa-layer-visibility.mjs

diff --git a/changelog.d/1282-polling-issue-fix.md b/changelog.d/1282-polling-issue-fix.md
index f3aede4e4..4af89eeee 100644
--- a/changelog.d/1282-polling-issue-fix.md
+++ b/changelog.d/1282-polling-issue-fix.md
@@ -2,3 +2,5 @@
 - Report and guard browser visibility during Transit QA so hidden-page polling pauses cannot masquerade as playback regressions (asturksever, #1282).
 - Require each live city to supply its own feed vehicles in Transit QA; retained vehicles cannot qualify another city (asturksever, #1282).
 - Bound the Transit card-anchor probe by observed poll coverage instead of a fixed 20-second window (asturksever, #1282).
+- Keep visible-page Transit probes focused through the browser testing API (asturksever, #1282).
+- Add a real-browser regression gate for hidden-tab periodic work, explicit refresh, resume and teardown (asturksever, #1282).
diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index 508b6264d..3eacee1c6 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -4002,6 +4002,8 @@ animation. Polls, surface completions and trail fades request individual renders
 Disable clears vehicles, detection references, requests, timers and holds;
 destruction also releases collections and registrations.
 
+The `scripts/qa-layer-visibility.mjs` gate uses the development-only registration seam and real browser tab visibility to prove periodic work pauses while hidden, explicit refresh still works, resume performs one overdue refresh, and disabled layers stay stopped.
+
 **Acceptance harness.** Run against an already running development server:
 
 ```sh
diff --git a/scripts/format-scope.json b/scripts/format-scope.json
index 543b0f9a4..b894cbe9a 100644
--- a/scripts/format-scope.json
+++ b/scripts/format-scope.json
@@ -1070,5 +1070,6 @@
   "scripts/assemble-changelog.mjs",
   "src/tooling/changelogFragments.test.mjs",
   "src/data/gbfsProxyRateLimit.test.mjs",
-  "src/terrainHeightsBounds.test.mjs"
+  "src/terrainHeightsBounds.test.mjs",
+  "scripts/qa-layer-visibility.mjs"
 ]
diff --git a/scripts/qa-layer-visibility.mjs b/scripts/qa-layer-visibility.mjs
new file mode 100644
index 000000000..8a903918e
--- /dev/null
+++ b/scripts/qa-layer-visibility.mjs
@@ -0,0 +1,124 @@
+#!/usr/bin/env node
+/**
+ * Real-browser proof for manager-owned periodic work and document visibility.
+ * Uses the app's development-only layer registration seam; no provider keys.
+ * Run: node scripts/qa-layer-visibility.mjs --url http://localhost:4173
+ * Hiding uses a real background tab, never a patched document.hidden getter.
+ */
+import assert from 'node:assert/strict';
+import puppeteer from 'puppeteer';
+import { chromeExecutablePath } from './qa-chrome.mjs';
+
+const args = process.argv.slice(2);
+const urlIndex = args.indexOf('--url');
+const url = new URL(
+  (urlIndex >= 0 ? args[urlIndex + 1] : undefined) ||
+    process.env.QA_BASE_URL ||
+    'http://localhost:4173',
+);
+url.searchParams.set('welcome', '0');
+const browser = await puppeteer.launch({
+  executablePath: chromeExecutablePath(),
+  headless: true,
+  args: [
+    '--no-sandbox',
+    '--disable-background-timer-throttling',
+    '--disable-renderer-backgrounding',
+  ],
+});
+const pause = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
+const check = (name, actual, expected) => {
+  assert.equal(actual, expected, name);
+  console.log(`PASS ${name}: ${actual}`);
+};
+try {
+  const page = await browser.newPage();
+  const focus = await page.createCDPSession();
+  await focus.send('Emulation.setFocusEmulationEnabled', { enabled: true });
+  await page.goto(url.href, { waitUntil: 'domcontentloaded' });
+  await page.waitForFunction(
+    () => window.__gevQaRegisterLayer && window.__godsEyeView?.dataManager,
+  );
+  await page.evaluate(async () => {
+    const manager = window.__godsEyeView.dataManager;
+    window.__qaVisibilityUpdates = 0;
+    window.__gevQaRegisterLayer(manager, {
+      id: 'qa-document-visibility',
+      name: 'Visibility QA',
+      updateInterval: 750,
+      init() {},
+      enable() {},
+      disable() {},
+      destroy() {},
+      async update() {
+        window.__qaVisibilityUpdates++;
+        return true;
+      },
+      getStats() {
+        return { count: window.__qaVisibilityUpdates };
+      },
+    });
+    await manager.setEnabled('qa-document-visibility', true, { origin: 'qa' });
+  });
+  const count = () => page.evaluate(() => window.__qaVisibilityUpdates);
+  await page.waitForFunction(() => window.__qaVisibilityUpdates >= 3);
+  check('periodic updates run while visible', (await count()) >= 3, true);
+  await focus.send('Emulation.setFocusEmulationEnabled', { enabled: false });
+  const cover = await browser.newPage();
+  await cover.bringToFront();
+  await page.waitForFunction(() => document.visibilityState === 'hidden');
+  const hiddenCount = await count();
+  await pause(2200);
+  check('hidden tab makes no periodic updates', await count(), hiddenCount);
+  check(
+    'explicit refresh remains available while hidden',
+    await page.evaluate(() =>
+      window.__godsEyeView.dataManager.refreshLayer('qa-document-visibility'),
+    ),
+    true,
+  );
+  check('explicit hidden refresh runs once', await count(), hiddenCount + 1);
+  await focus.send('Emulation.setFocusEmulationEnabled', { enabled: true });
+  await page.waitForFunction(
+    () =>
+      document.visibilityState === 'visible' &&
+      window.__qaVisibilityUpdates > 0,
+  );
+  await pause(200);
+  check(
+    'resume performs one overdue refresh without a catch-up burst',
+    await count(),
+    hiddenCount + 2,
+  );
+  await page.evaluate(() =>
+    window.__godsEyeView.dataManager.setEnabled(
+      'qa-document-visibility',
+      false,
+      { origin: 'qa' },
+    ),
+  );
+  const stopped = await count();
+  await focus.send('Emulation.setFocusEmulationEnabled', { enabled: false });
+  await cover.bringToFront();
+  await page.waitForFunction(() => document.visibilityState === 'hidden');
+  await focus.send('Emulation.setFocusEmulationEnabled', { enabled: true });
+  await pause(1100);
+  check(
+    'disabled layer does not resume on visibility change',
+    await count(),
+    stopped,
+  );
+  check(
+    'QA layer destroys cleanly',
+    await page.evaluate(() =>
+      window.__gevQaUnregisterLayer(
+        window.__godsEyeView.dataManager,
+        'qa-document-visibility',
+      ),
+    ),
+    true,
+  );
+  console.log('RESULT: 7 passed');
+} finally {
+  await browser.close();
+}
diff --git a/scripts/qa-transit.mjs b/scripts/qa-transit.mjs
index 628983e74..47eafc94d 100644
--- a/scripts/qa-transit.mjs
+++ b/scripts/qa-transit.mjs
@@ -275,6 +275,10 @@ const browser = await puppeteer.launch({
   ],
 });
 const page = await browser.newPage();
+// This gate measures visible-page motion. OS minimization must not silently
+// switch it into the app's intentional hidden-tab polling pause.
+const focus = await page.createCDPSession();
+await focus.send('Emulation.setFocusEmulationEnabled', { enabled: true });
 boundPageEvaluations(page);
 await page.setViewport({ width: 1920, height: 1080 });
 const pageErrors = [];

From 72f1625257d14702e5a911958ab72c70264ee3e5 Mon Sep 17 00:00:00 2001
From: Said <asturksever@Saids-MacBook-Air.local>
Date: Tue, 20 Oct 2026 14:43:01 +0100
Subject: [PATCH 08/10] test: avoid concurrent format-scope append conflicts

---
 scripts/format-scope.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/format-scope.json b/scripts/format-scope.json
index b894cbe9a..92bd228ba 100644
--- a/scripts/format-scope.json
+++ b/scripts/format-scope.json
@@ -4,6 +4,7 @@
   "scripts/format-scope.json",
   "scripts/package-boundaries.json",
   "scripts/format.mjs",
+  "scripts/qa-layer-visibility.mjs",
   "scripts/next-layer-state-token.mjs",
   "scripts/check-layer-state-tokens.mjs",
   "scripts/qa-layer-token-twochar.mjs",
@@ -1070,6 +1071,5 @@
   "scripts/assemble-changelog.mjs",
   "src/tooling/changelogFragments.test.mjs",
   "src/data/gbfsProxyRateLimit.test.mjs",
-  "src/terrainHeightsBounds.test.mjs",
-  "scripts/qa-layer-visibility.mjs"
+  "src/terrainHeightsBounds.test.mjs"
 ]

From 56be69d065c4e77d46ec034075327155eb520940 Mon Sep 17 00:00:00 2001
From: Said <asturksever@Saids-MacBook-Air.local>
Date: Tue, 20 Oct 2026 15:12:33 +0100
Subject: [PATCH 09/10] test: restore minimized Transit windows before
 screenshots

---
 changelog.d/1282-polling-issue-fix.md |  1 +
 scripts/qa-chrome.mjs                 | 27 +++++++++++++
 scripts/qa-transit-recovery.mjs       |  4 +-
 scripts/qa-transit-scenes.mjs         | 13 +++---
 scripts/qa-transit.mjs                | 14 ++++---
 src/qaChrome.test.mjs                 | 57 ++++++++++++++++++++++++++-
 6 files changed, 101 insertions(+), 15 deletions(-)

diff --git a/changelog.d/1282-polling-issue-fix.md b/changelog.d/1282-polling-issue-fix.md
index 4af89eeee..9931385bf 100644
--- a/changelog.d/1282-polling-issue-fix.md
+++ b/changelog.d/1282-polling-issue-fix.md
@@ -4,3 +4,4 @@
 - Bound the Transit card-anchor probe by observed poll coverage instead of a fixed 20-second window (asturksever, #1282).
 - Keep visible-page Transit probes focused through the browser testing API (asturksever, #1282).
 - Add a real-browser regression gate for hidden-tab periodic work, explicit refresh, resume and teardown (asturksever, #1282).
+- Restore minimized test windows before screenshots so native compositor pauses cannot stall browser acceptance (asturksever, #1282).
diff --git a/scripts/qa-chrome.mjs b/scripts/qa-chrome.mjs
index 05c4dbff0..2416a04e3 100644
--- a/scripts/qa-chrome.mjs
+++ b/scripts/qa-chrome.mjs
@@ -18,3 +18,30 @@ export function chromeExecutablePath({
   if (env.PUPPETEER_EXECUTABLE_PATH) return env.PUPPETEER_EXECUTABLE_PATH;
   return exists(MACOS_CHROME) ? MACOS_CHROME : undefined;
 }
+
+/** Restore an owned test window before capture: focus emulation alone does not
+ * unminimize the native compositor, so CDP screenshots can otherwise stall. */
+export async function captureQaScreenshot(
+  page,
+  options,
+  { headful = true } = {},
+) {
+  if (headful) {
+    const session = await page.createCDPSession();
+    try {
+      const { windowId, bounds } = await session.send(
+        'Browser.getWindowForTarget',
+      );
+      if (bounds.windowState === 'minimized') {
+        await session.send('Browser.setWindowBounds', {
+          windowId,
+          bounds: { windowState: 'normal' },
+        });
+      }
+      await page.bringToFront();
+    } finally {
+      await session.detach();
+    }
+  }
+  return page.screenshot(options);
+}
diff --git a/scripts/qa-transit-recovery.mjs b/scripts/qa-transit-recovery.mjs
index 5f6404b41..a54e81239 100644
--- a/scripts/qa-transit-recovery.mjs
+++ b/scripts/qa-transit-recovery.mjs
@@ -1,6 +1,6 @@
 /** Camera-jump regression against an existing server; never starts a server. */
 import puppeteer from 'puppeteer';
-import { chromeExecutablePath } from './qa-chrome.mjs';
+import { chromeExecutablePath, captureQaScreenshot } from './qa-chrome.mjs';
 import { mkdir, writeFile } from 'node:fs/promises';
 import { reduceTrailPixels } from '../src/layers/transit/qaMetrics.js';
 
@@ -307,7 +307,7 @@ try {
   result.pixelPass = pixels.pass;
   result.pixelDetails = pixels;
   result.errors = errors;
-  await page.screenshot({ path: `${shots}/recovery.png` });
+  await captureQaScreenshot(page, { path: `${shots}/recovery.png` });
   await writeFile(`${shots}/recovery.json`, JSON.stringify(result, null, 2));
   for (const key of ['on', 'off', 'onAgain', 'offAgain']) delete result[key];
   const pass =
diff --git a/scripts/qa-transit-scenes.mjs b/scripts/qa-transit-scenes.mjs
index 1ceb45b22..f325cb9f7 100644
--- a/scripts/qa-transit-scenes.mjs
+++ b/scripts/qa-transit-scenes.mjs
@@ -1,3 +1,4 @@
+import { captureQaScreenshot } from './qa-chrome.mjs';
 import { getRegisteredTransitFeed } from '../src/data/transitFeeds.js';
 
 // Not registered or active: camera discovery and live polls never own this feed.
@@ -219,7 +220,7 @@ export async function runFleetBudgets({
         allocations.layerFrameBytes / allocationTrace.rows.length <= 8192,
       `${allocations.layerFrameBytes / allocationTrace.rows.length} transit-authored bytes/frame; whole frame ${allocations.frameBytes / allocationTrace.rows.length}; top three ${JSON.stringify(details.topAllocatorsPerFrame)}; collected objects included. Full profile saved.`,
     );
-    await page.screenshot({
+    await captureQaScreenshot(page, {
       path: `${shots}/${tag}-fleet-${count}.jpg`,
       type: 'jpeg',
       quality: 85,
@@ -392,7 +393,7 @@ export async function runBostonMatrix({
         JSON.stringify({ pixels, contrast }),
         { unexercised: pixels.length < 6 },
       );
-      await page.screenshot({
+      await captureQaScreenshot(page, {
         path: `${shots}/${tag}-matrix-${background.name}-${look.name}-fleet.jpg`,
         type: 'jpeg',
         quality: 90,
@@ -407,7 +408,7 @@ export async function runBostonMatrix({
           target.key,
         );
         await wait(500);
-        await page.screenshot({
+        await captureQaScreenshot(page, {
           path: `${shots}/${tag}-matrix-${background.name}-${look.name}-${target.route}-selected.jpg`,
           type: 'jpeg',
           quality: 90,
@@ -431,7 +432,7 @@ export async function runBostonMatrix({
         );
       }
       await wait(300);
-      await page.screenshot({
+      await captureQaScreenshot(page, {
         path: `${shots}/${tag}-matrix-${background.name}-${look.name}-restored.jpg`,
         type: 'jpeg',
         quality: 90,
@@ -579,7 +580,7 @@ export async function runBostonLive({
       JSON.stringify(selection),
       { unexercised: !target },
     );
-    await page.screenshot({
+    await captureQaScreenshot(page, {
       path: `${shots}/${tag}-boston-live-${view.name}.jpg`,
       type: 'jpeg',
       quality: 90,
@@ -1010,7 +1011,7 @@ export async function runTrailVisibility({
     stable: pixels.stable[i],
     eligible: pixels.eligible[i],
   }));
-  await page.screenshot({
+  await captureQaScreenshot(page, {
     path: `${shots}/${tag}-${altitude}m-trail-visible.jpg`,
     type: 'jpeg',
     quality: 95,
diff --git a/scripts/qa-transit.mjs b/scripts/qa-transit.mjs
index 47eafc94d..943e39df5 100644
--- a/scripts/qa-transit.mjs
+++ b/scripts/qa-transit.mjs
@@ -36,7 +36,7 @@ import {
  */
 import { mkdir, readFile, writeFile } from 'node:fs/promises';
 import puppeteer from 'puppeteer';
-import { chromeExecutablePath } from './qa-chrome.mjs';
+import { chromeExecutablePath, captureQaScreenshot } from './qa-chrome.mjs';
 import { createTransitHistory } from '../server/providers/transitHistory.js';
 import { DETECTION_THEME_MAP } from '../src/overlays/worldOverlayTokens.js';
 import { transitModeTier } from '../src/data/transitPresetStyle.js';
@@ -294,11 +294,13 @@ page.on('request', (request) => {
 });
 
 const shot = (name, caption) =>
-  page
-    .screenshot({ path: `${SHOTS}/${name}`, type: 'jpeg', quality: 82 })
-    .then(() => {
-      console.log(`  shot ${name} — ${caption}`);
-    });
+  captureQaScreenshot(page, {
+    path: `${SHOTS}/${name}`,
+    type: 'jpeg',
+    quality: 82,
+  }).then(() => {
+    console.log(`  shot ${name} — ${caption}`);
+  });
 
 const view = (city) =>
   `${BASE}/?welcome=0#lat=${city.lat}&lon=${city.lon}&alt=600&heading=${city.heading}&pitch=-45`;
diff --git a/src/qaChrome.test.mjs b/src/qaChrome.test.mjs
index 4414f3c93..398d23ab3 100644
--- a/src/qaChrome.test.mjs
+++ b/src/qaChrome.test.mjs
@@ -1,6 +1,10 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
-import { MACOS_CHROME, chromeExecutablePath } from '../scripts/qa-chrome.mjs';
+import {
+  MACOS_CHROME,
+  chromeExecutablePath,
+  captureQaScreenshot,
+} from '../scripts/qa-chrome.mjs';
 
 test('gates keep macOS Chrome where it is installed', () => {
   assert.equal(
@@ -25,3 +29,54 @@ test('an explicit executable path wins', () => {
     'C:\\Chrome\\chrome.exe',
   );
 });
+
+test('screenshots restore minimized test windows before capture and detach their session', async () => {
+  const calls = [];
+  const session = {
+    send: async (method, params) => {
+      calls.push([method, params]);
+      return { windowId: 7, bounds: { windowState: 'minimized' } };
+    },
+    detach: async () => calls.push(['detach']),
+  };
+  const page = {
+    createCDPSession: async () => session,
+    bringToFront: async () => calls.push(['front']),
+    screenshot: async (options) => {
+      calls.push(['capture', options]);
+      return 'pixels';
+    },
+  };
+  assert.equal(
+    await captureQaScreenshot(page, { path: 'proof.png' }),
+    'pixels',
+  );
+  assert.deepEqual(
+    calls.map((c) => c[0]),
+    [
+      'Browser.getWindowForTarget',
+      'Browser.setWindowBounds',
+      'front',
+      'detach',
+      'capture',
+    ],
+  );
+  assert.deepEqual(calls[1][1], {
+    windowId: 7,
+    bounds: { windowState: 'normal' },
+  });
+});
+
+test('headless capture does not manipulate a native window', async () => {
+  const options = { path: 'proof.png' };
+  const page = {
+    screenshot: async (supplied) => {
+      assert.equal(supplied, options);
+      return 'pixels';
+    },
+  };
+  assert.equal(
+    await captureQaScreenshot(page, options, { headful: false }),
+    'pixels',
+  );
+});

From 07d6417446f4e1f724e392147bacce73713f8093 Mon Sep 17 00:00:00 2001
From: Said Turksever <asturksever@gmail.com>
Date: Fri, 23 Oct 2026 12:22:42 +0100
Subject: [PATCH 10/10] Realign periodic polling to the deadline after a
 visibility catch-up

An overdue refresh on return to a visible tab advanced the due time but kept
the old setInterval phase, so the next phase tick was skipped and the gap
could approach two intervals (also after a failed resume refresh). The
catch-up now re-arms the interval at the new deadline. Interval ticks no
longer compare against the due time, since the phase and the deadline share
one origin. Overlap prevention and teardown are unchanged, and a stale
listener cannot re-arm a stopped loop.

Tests cover the next poll one interval after a between-ticks resume, with a
successful and a failed catch-up refresh.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 changelog.d/1282-polling-issue-fix.md |  2 +-
 docs/CURRENT-STATE.md                 |  2 +-
 src/data/lifecycle.js                 | 48 +++++++++++++++-------
 src/data/manager.test.mjs             | 58 +++++++++++++++++++++++++++
 4 files changed, 94 insertions(+), 16 deletions(-)

diff --git a/changelog.d/1282-polling-issue-fix.md b/changelog.d/1282-polling-issue-fix.md
index 9931385bf..98885fc20 100644
--- a/changelog.d/1282-polling-issue-fix.md
+++ b/changelog.d/1282-polling-issue-fix.md
@@ -1,4 +1,4 @@
-- Pause periodic network updates in hidden tabs (asturksever, #1282).
+- Pause periodic network updates in hidden tabs; the overdue update on return restarts the polling schedule, so the next poll follows one interval later even when that update fails (asturksever, #1282).
 - Report and guard browser visibility during Transit QA so hidden-page polling pauses cannot masquerade as playback regressions (asturksever, #1282).
 - Require each live city to supply its own feed vehicles in Transit QA; retained vehicles cannot qualify another city (asturksever, #1282).
 - Bound the Transit card-anchor probe by observed poll coverage instead of a fixed 20-second window (asturksever, #1282).
diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index 8b3827634..3cb2493e2 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -9,7 +9,7 @@ broader suffix variants. Follow-ups retain boundary provenance, and cancelled
 lookups preserve the previous analyst cohort and boundary source. Navigation
 search keeps a successful geocode, with no search or view-based region recovery.
 
-Manager-owned periodic network updates pause while the document is hidden. Returning to a visible tab runs one overdue update per enabled layer without overlapping an active refresh; explicit refresh requests remain available. Transit also defers camera-driven feed admission while hidden and rechecks coverage on return. Visibility listeners are released with their polling intervals.
+Manager-owned periodic network updates pause while the document is hidden. Returning to a visible tab runs one overdue update per enabled layer without overlapping an active refresh and restarts that layer's polling schedule from the return, so the next poll follows one interval later whether or not the catch-up update succeeds; explicit refresh requests remain available. Transit also defers camera-driven feed admission while hidden and rechecks coverage on return. Visibility listeners are released with their polling intervals.
 
 Terrain height requests accept at most 64 points, matching the browser service's
 existing batch size and one bounded upstream chunk. Larger requests return HTTP
diff --git a/src/data/lifecycle.js b/src/data/lifecycle.js
index 01aaf6124..c8946e7bb 100644
--- a/src/data/lifecycle.js
+++ b/src/data/lifecycle.js
@@ -553,24 +553,44 @@ export class LayerLifecycle {
           : 0;
     if (refreshInterval > 0) {
       const visibilityDocument = this._visibilityTarget;
-      let dueAt = Date.now() + refreshInterval;
-      const tick = () => {
-        if (
-          visibilityDocument?.hidden ||
-          visibilityDocument?.visibilityState === 'hidden' ||
-          !entry.enabled ||
-          entry.destroying ||
-          entry.refreshing ||
-          Date.now() < dueAt
-        )
-          return;
+      let intervalId = null;
+      let dueAt = 0;
+      const canPoll = () =>
+        !visibilityDocument?.hidden &&
+        visibilityDocument?.visibilityState !== 'hidden' &&
+        entry.enabled &&
+        !entry.destroying &&
+        !entry.refreshing &&
+        entry.intervalId === intervalId;
+      // dueAt and the interval phase share one origin, so every interval tick
+      // is a due poll. A visibility catch-up re-arms the interval at the new
+      // deadline; otherwise the old phase would skip its next tick.
+      const schedule = () => {
+        clearInterval(intervalId);
+        dueAt = Date.now() + refreshInterval;
+        intervalId = setInterval(onInterval, refreshInterval);
+        entry.intervalId = intervalId;
+      };
+      const onInterval = () => {
+        if (!canPoll()) return;
         dueAt = Date.now() + refreshInterval;
         void this._runPeriodicUpdate(layerId, entry);
       };
-      entry.intervalId = setInterval(tick, refreshInterval);
-      visibilityDocument?.addEventListener?.('visibilitychange', tick);
+      const onVisibilityChange = () => {
+        if (!canPoll() || Date.now() < dueAt) return;
+        schedule();
+        void this._runPeriodicUpdate(layerId, entry);
+      };
+      schedule();
+      visibilityDocument?.addEventListener?.(
+        'visibilitychange',
+        onVisibilityChange,
+      );
       entry.removeVisibilityListener = () =>
-        visibilityDocument?.removeEventListener?.('visibilitychange', tick);
+        visibilityDocument?.removeEventListener?.(
+          'visibilitychange',
+          onVisibilityChange,
+        );
     } else if (updateInterval === 0) {
       entry.intervalId = setInterval(() => {
         if (!entry.enabled) return;
diff --git a/src/data/manager.test.mjs b/src/data/manager.test.mjs
index 68a0644f1..b1384a2de 100644
--- a/src/data/manager.test.mjs
+++ b/src/data/manager.test.mjs
@@ -3523,3 +3523,61 @@ test('periodic polls pause hidden, catch up once when due, and dispose visibilit
   t.mock.timers.tick(10000);
   assert.equal(calls.update, 3);
 });
+
+async function resumeBetweenTicks(t, { failResume = false } = {}) {
+  const listeners = new Set();
+  const doc = {
+    hidden: false,
+    addEventListener: (_name, fn) => listeners.add(fn),
+    removeEventListener: (_name, fn) => listeners.delete(fn),
+  };
+  t.mock.timers.enable({ apis: ['setInterval', 'Date'], now: 1000 });
+  const { LayerLifecycle } = await import('./lifecycle.js');
+  const manager = new LayerLifecycle({}, { visibilityTarget: doc });
+  const { module, calls } = makeSlowLayer('resume-poll');
+  const updates = [];
+  module.update = async () => {
+    calls.update++;
+    updates.push(Date.now());
+    await Promise.resolve();
+    if (failResume && updates.length === 2) throw new Error('resume failed');
+  };
+  manager.register(module);
+  await manager.setEnabled('resume-poll', true);
+  assert.deepEqual(updates, [1000]);
+  doc.hidden = true;
+  t.mock.timers.tick(1000); // 2000: due tick skipped while hidden
+  t.mock.timers.tick(500); // 2500: return between ticks
+  doc.hidden = false;
+  for (const fn of listeners) fn();
+  assert.deepEqual(updates, [1000, 2500], 'overdue poll runs once on return');
+  await Promise.resolve();
+  await Promise.resolve();
+  await Promise.resolve();
+  const managerRefreshError = manager.layers.get('resume-poll').managerRefreshError;
+  if (failResume) assert.equal(managerRefreshError, 'resume failed');
+  else assert.equal(managerRefreshError, null);
+  t.mock.timers.tick(999); // 3499: the old 3000 phase must not fire
+  assert.deepEqual(updates, [1000, 2500]);
+  t.mock.timers.tick(1); // 3500: one interval after the resume poll
+  assert.deepEqual(updates, [1000, 2500, 3500]);
+  await Promise.resolve();
+  await Promise.resolve();
+  await Promise.resolve();
+  t.mock.timers.tick(1000);
+  assert.deepEqual(updates, [1000, 2500, 3500, 4500], 'new phase keeps one interval');
+  await Promise.resolve();
+  await Promise.resolve();
+  await manager.destroyAll();
+  assert.equal(listeners.size, 0);
+  t.mock.timers.tick(5000);
+  assert.equal(updates.length, 4);
+}
+
+test('periodic polls realign to the deadline after a between-ticks resume', async (t) => {
+  await resumeBetweenTicks(t);
+});
+
+test('periodic polls realign to the deadline after a failed resume refresh', async (t) => {
+  await resumeBetweenTicks(t, { failResume: true });
+});