[build-tools] Avoid cold runtime scans with preinstalled WDA

[gwdp]

Why

Cold WDA startup can trigger a slow Simulator runtime scan.

How

Use Appium’s matching preinstalled WDA runner, with a bounded download and fallback to xcodebuild. Security protections stay enabled.

Test Plan

We observed the cold-start delay on hosted EAS. After deployment, confirm on fresh EAS workers that the long first-session delay is gone and recordings remain complete.

Hosted Xcode 26.6/iOS 26.5: 110s → 6.8/7.3s, with complete 150s recordings. Tart Xcode 27/iOS 27: cold startup, app interaction, and 150s recording passed with matching packages and 5 CPU/20 GB. 58 focused tests and Node 22/24 CI passed.

Authorship and LLM use

Gabe directed the work and reviewed the final changes. Codex implemented and tested it.

— Codex

[github-actions]

✅ Thank you for adding the changelog entry!

[codecov]

Codecov Report

❌ Patch coverage is 95.45455% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 74.36%. Comparing base (3b59a74) to head (ad3ac97).

Files with missing lines	Patch %	Lines
...ges/build-tools/src/steps/utils/preinstalledWda.ts	95.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4618      +/-   ##
==========================================
+ Coverage   74.35%   74.36%   +0.02%     
==========================================
  Files        1027     1028       +1     
  Lines       50178    50200      +22     
  Branches    10848    10851       +3     
==========================================
+ Hits        37303    37325      +22     
  Misses      11884    11884              
  Partials      991      991              

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.