Add a typed Playwright harness for Pagefind and the Apple Silicon app-test flow so scanner work has browser-level protection. Keep the rollout plan in the same stack so the TypeScript conversion stays staged and reviewable.
Constraint: Must not change production runtime behavior in this commit
Rejected: Leave the old JS browser test and add a second harness | duplicates setup and leaves the targeted browser script broken
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Keep browser-only helpers under test/playwright/support until the runtime scanner surface is fully typed
Tested: pnpm run typecheck; pnpm run test:browser; pnpm run test:browser:pagefind
Not-tested: Live browser checks against doesitarm.com
Capture user-visible parity requirements for a future Pagefind migration.
This keeps the earlier viability memo focused on engine fit and documents the recommended adapter approach, carry-over patterns, and remaining prototype risks around ranking and title highlighting.
