Fix Apple Silicon CI build failure by validating cached CocoaPods state

[Copilot]

Build Apple Silicon failed because CI reused a cached Pods/ directory even when it no longer matched Podfile.lock, triggering [CP] Check Pods Manifest.lock errors. This updates dependency install gating so stale CocoaPods caches are automatically reconciled.

• Root-cause fix: cache validity check before skipping pod install

  • In .github/workflows/build.yml, both build-apple-silicon and build-intel now run pod install --repo-update unless all of the following are true:
    • Pods/ exists
    • Pods/Manifest.lock exists
    • Pods/Manifest.lock matches Podfile.lock

• Behavioral impact

  • Keeps the fast path for valid cache hits.
  • Prevents lock/manifest drift from breaking architecture-specific builds.

if [ ! -d "Pods" ] || [ ! -f "Pods/Manifest.lock" ] || ! cmp -s "Podfile.lock" "Pods/Manifest.lock"; then
  pod install --repo-update
else
  echo "Using cached Pods"
fi

[Copilot]

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