fix(screencast): keep overlays above top layer elements

[Pavel Feldman (pavelfeldman)]

Summary

• Re-promote the glass pane into the top layer on every highlight use, so overlays shown after a dialog or popover opened paint above it.
• While user overlays are showing, keep re-promoting the pane on a timer, so dialogs and popovers opened later do not cover it.

Fixes #42629

[github-actions]

Test results for "tests 1"

9 flaky

⚠️ [chromium-library] › library/video.spec.ts:664 › screencast › should capture full viewport `@frozen-time-library-chromium-linux`
⚠️ [chromium-library] › library/video.spec.ts:699 › screencast › should capture full viewport on hidpi `@frozen-time-library-chromium-linux`
⚠️ [chromium-library] › library/browsercontext-page-event.spec.ts:160 › should work with Shift-clicking `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/popup.spec.ts:260 › should not throw when click closes popup `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/beforeunload.spec.ts:130 › should support dismissing the dialog multiple times `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/popup.spec.ts:260 › should not throw when click closes popup `@chromium-ubuntu-22.04-node24`
⚠️ [firefox-library] › library/browsercontext-cookies-third-party.spec.ts:257 › third party 'Partitioned;' cookies `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-library] › library/browsercontext-cookies-third-party.spec.ts:470 › top level 'Partitioned;' cookie and same origin iframe `@firefox-ubuntu-22.04-node20`
⚠️ [playwright-test] › ui-mode-trace.spec.ts:388 › should reveal errors in the sourcetab `@windows-latest-node22`

51452 passed, 1246 skipped

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Merge workflow run.

[github-actions]

🟢 CI is clear — the failures are pre-existing firefox flakes

Hi, I'm the Playwright bot and I took a first look at the failing CI.

Nothing here looks caused by this PR. The tests 1 report has no real failures (9 flaky, all rescued on retry). The only reds are 4 firefox MCP tests, and every one of them has a long history of flaking on unrelated SHAs and PRs — including main pushes — well before this branch. This PR only touches the injected highlight/overlay glass pane (highlight.ts, injectedScript.ts) and its screencast-overlay test; it doesn't go near the MCP http transport, annotate CDP path, or the devtools CLI part-extraction those tests exercise.

Details

Overall: worst per-group call is green. The 4 MCP failures are all firefox-only, all bimodal (pass the overwhelming majority of runs), and all fail on many SHAs this PR can't be responsible for.

Pre-existing flake / infra

• [firefox] › mcp/http.spec.ts:105 › http transport browser lifecycle (isolated) — flips verdict across runs on firefox: failed 5 of 714 runs, passed the rest. Also flakes on chromium/msedge/webkit. Reds on unrelated pushes (aeebee1d, 5ea7ac2c, 13dbf102, …) and PRs fix(mcp): follow symlinks when checking file access against workspace roots #42628, fix(recorder): keep recordings separate per client on a shared context #42615, fix(cli): parse negative numbers as arguments #42333, chore(deps-dev): bump js-yaml from 4.3.0 to 4.3.1 #42159 going back to early August.
• [firefox] › mcp/annotate.spec.ts:291 › should enter annotate mode on fresh dashboard.tsx mount with -s --annotate — failed 6 of 714 firefox runs, 5 more rescued within-run. Reds on push 5812882a and PRs feat(ct): type mount() story ids through a generated Stories registry #42518, fix(cli): stop daemon when socket disappears #42454, docs(browsercontext): undeprecate setHTTPCredentials #42419, fix(trace-viewer): store snapshot style text in an attribute #42405, chore(net): use native happy eyeballs instead of the manual implementation #42240 — none related to this branch.
• [firefox] › mcp/annotate.spec.ts:316 › should annotate via direct browser_annotate MCP call — failed 3 of 714 firefox runs. Reds on push 13dbf102 and PRs fix(recorder): keep recordings separate per client on a shared context #42615, feat(ct): type mount() story ids through a generated Stories registry #42518, fix(cli): stop daemon when socket disappears #42454, test: race between disabling interception and network request in chromium #42254, chore: mark v1.62.1 #42020.
• [firefox] › mcp/cli-devtools.spec.ts:115 › per-part commands extract individual parts — failed 9 of 714 firefox runs, green on every other browser. Reds spread across PRs fix(mcp): time out extension connection when a token is passed #42525, chore(extension): bump version to 0.4.0 #42482, chore(video): emit frames with real timestamps, drop frame number quantization #42480, fix(tracing): allow restarting tracing after a failed stop #42425, feat(mcp): add browser_emulate_media tool and --color-scheme option #42244, fix(extension): do not treat orphaned preferences entries as an installed extension #42224, chore: remove experimental component testing #42168, feat(trace-viewer): show test annotations in the trace viewer #42060, chore: mark v1.62.1 #42020 and push d0c1b736, back to late July.

The overlay change here is Chromium/screencast-facing and lives entirely in the glass-pane promotion logic; the annotate flow uses highlights but fails on firefox independent of this diff, so the connection is coincidental, not causal.

_{Triaged by the Playwright bot - agent run}

[github-actions]

Test results for "MCP"

8348 passed, 1376 skipped

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Merge workflow run.