fix(cli): respect pointer-transparent text in occlusion checks

[miguel-heygen]

What

hyperframes check no longer reports captions as hidden by a background video when the captions are visibly painted above it with pointer-events: none.

Why

The occlusion audit relied on document.elementFromPoint(), which intentionally skips pointer-transparent content. Caption rails commonly disable pointer events, so the audit saw the video underneath and produced a blocking text_occluded false positive despite correct z-index and verified rendered output.

How

During each occlusion probe, pointer-transparent text is made hit-testable just long enough to query the true paint order. Its authored inline value and priority are restored immediately afterward. A regression test covers a video beneath pointer-transparent text and verifies that the original style survives the audit.

Test plan

• Added a regression test and observed it fail before the fix
• bun run --cwd packages/cli test -- src/commands/layout-audit.browser.test.ts (39 passed)
• bun run --cwd packages/cli test (1,650 passed)
• CLI typecheck, lint, formatting, and commit hooks passed
• Reproduced with a real video/caption fixture on 0.7.56, then verified the local CLI returns zero layout findings

---