fix(media): validate the actual browser-client provenance

[alphastorm]

Fix

• Use the vendored browser-client provenance file, not the independent OMP host lock, in both media capture and validation.
• Replace obsolete editorial-copy waits with observable session/notification/request state. Preserve fixture-label, exact-launch, privacy, geometry, and codec checks.
• Add a portable regression that failed on the previous pin source and passes with the fix.

Verification

• Full local synthetic capture and strict media:check passed with this source; 8 regenerated assets and zero unexpected runtime/compositor requests.
• Two successful captures produced identical binary hashes.
• 11 focused tests / 78 assertions, repository check, capability and identifier leak scans passed.
• Real regenerated client and notification captures inspected.

Publication ordering

This PR contains the source fix, not the regenerated binaries. Once squash-merged, regenerate against that permanent main commit and publish the media in a separate PR. This keeps the manifest sourceRevision reachable from main. Until that second PR, the existing historical media still fails current-pin validation. No gate bypass, release, runtime change, or expanded qualification claim.

[codecov]

Codecov Report

❌ Patch coverage is 77.77778% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 61.03%. Comparing base (b193949) to head (538c044).

Files with missing lines	Patch %	Lines
scripts/media/check-readme-media.ts	77.77%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #175      +/-   ##
==========================================
- Coverage   65.49%   61.03%   -4.47%     
==========================================
  Files          33       35       +2     
  Lines        8875     9683     +808     
==========================================
+ Hits         5813     5910      +97     
- Misses       3062     3773     +711     

Files with missing lines	Coverage Δ
scripts/media/check-readme-media.ts	12.18% <77.77%> (ø)

... and 2 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[alphastorm]

All executable CI jobs and both required checks passed. The Codecov project advisory reports 65.49% → 61.03%: importing the media gate for the new regression adds two previously unmeasured modules / 808 executable lines; covered lines increase by 97. Retaining this measurement rather than excluding code or padding tests. The real full capture and strict media gate also passed locally; those runs were not coverage-instrumented. Fleet source verification passed: https://github.com/alphastorm/omp-session-gateway/actions/runs/34863305669 .