Road to 0.83

[Saadnajmi]

Tracking issue for the merge-up from upstream 0.83-stable (facebook/react-native).
Work is happening on the 0.83-merge branch.

• Merge chore: merge up to 0.83-stable branch #2824 — Initial 0.83-stable merge into 0.83-merge branch
• CI for merge branches — Add *-merge to workflow triggers (microsoft-pr.yml, test-all.yml, publish-bumped-packages.yml, codeql-analysis.yml) so CI runs on 0.83-merge
• Hermes V1 support — From 0.83+, Hermes is published separately (com/facebook/hermes/hermes-ios) with its own versioning. Add version.properties, update hermes-engine.podspec and hermes-utils.rb to support RCT_HERMES_V1_ENABLED env var and new Maven coordinates, with findMatchingHermesVersion() fallback
• Audit upstream breaking changes — Review 0.83 release notes for breaking changes and update macOS-specific APIs as needed
• RNTester validation — Verify RNTester builds and runs on macOS, pod install works (both legacy and V1 Hermes)
• react-native-test-app integration — Test RNTA compatibility with 0.83 changes
• Merge 0.83-merge → main — Final review, all CI green, merge