test(compat): normalize real-device performance budgets - #1354

Closes #161

Summary

• add a BrowserStack compatibility performance check that runs on the existing real-device matrix
• pair each Effector workload with a comparable plain-JavaScript control in the same browser session and gate on the median workload/control ratio instead of one absolute millisecond threshold across dissimilar devices
• adapt iteration counts until the control clears the timer-resolution floor, alternate measurement order, and assert final state/update counts so no-op updates cannot look artificially fast
• emit one structured [compat/perf] JSON record per device for reproducible CI comparisons

Scope

Two compat files only: src/compat/perf.test.ts and the accompanying README section. No runtime library or package changes.

Validation

The branch is based on current master at 93dd907eb07c1f8b7cf8ec56691c4a58935b8225, is 2 commits ahead / 0 behind, and the existing COMPAT Jest projects already match src/compat/**/*.test.ts. A real BrowserStack execution requires the repository's BROWSERSTACK_USERNAME / BROWSERSTACK_ACCESS_KEY; I am not claiming a local real-device pass before those hosted credentials run.

IssueHunt bounty / compensation request

/claim #161

This PR is the original contribution by @woahwhattheheck for funded IssueHunt issue #161 (the GitHub issue advertises $100 in backer deposits). I request recognition and the applicable $100 bounty compensation if the maintainers accept this PR and the marketplace eligibility requirements are satisfied. Please confirm review/acceptance, official IssueHunt claim registration, payout identity, and payout timing. The funded badge does not establish an award, a successful registration, or money received.