test: add ios simulator screenrecord tests

[gmegidish]

Adds two screenrecord tests for the iOS simulator in test/simulator.spec.ts, mirroring the Android emulator tests (#249):

• --time-limit 5 -> validates the MP4 with ffprobe.
• no time limit -> sends SIGINT (Ctrl-C), validates the MP4.

Both assert a non-empty, ffprobe-decodable MP4 and that its dimensions match a screenshot. Unlike the emulator, the simulator records at native resolution (1170x2532 == screenshot), so the dimension assertion applies here.

Notes

• No production code change needed: the simulator records via xcrun simctl io ... recordVideo locally, and mobilecli signals that local process (the actual writer), so Ctrl-C finalizes the MP4 correctly. (The Android fix in fix: finalize android screenrecord mp4 on ctrl-c by signaling on-device process #249 was needed because the writer ran on-device and didn't receive the forwarded signal.)
• screenrecord emits progress on stderr (no JSON on stdout), so it can't use this file's JSON-parsing mobilecli() helper. Added dedicated runners that drive the binary directly while preserving the GOCOVERDIR coverage env.

Verification

Both tests pass on Test-iOS-26:

npx playwright test --project=simulator -g "screenrecord"
2 passed

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📥 Commits

Reviewing files that changed from the base of the PR and between 116ecc8 and 077fe5f.

📒 Files selected for processing (1)

• test/simulator.spec.ts

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Walkthrough

This PR adds iOS simulator screenrecord test coverage to test/simulator.spec.ts. The changes introduce the spawn import for direct process control, define a Dimensions type for tracking video/screenshot dimensions, add a new test suite with two screenrecord scenarios (one with --time-limit and another interrupted by Ctrl-C), and implement helper functions to drive the screenrecord binary, validate MP4 playability using ffprobe, extract PNG dimensions from the IHDR chunk, and verify that recorded video dimensions match screenshot dimensions.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 62.50% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately and concisely describes the main change: adding iOS simulator screenrecord tests to the test suite.
Description check	✅ Passed	The description is directly related to the changeset, providing context about the tests added, their purpose, relevant notes, and verification results.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch test/ios-simulator-screenrecord

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