feat: merge `0.83-merge` into main (#2949)

## Summary

Merge up to the merge base of `0.83-stable` (the first commit on the
upstream `0.83-stable` branch, `a034841fd68`), prepping this branch for
the 0.83 release. For the cross-platform 0.83 changes (React 19.2,
DevTools, Web Performance APIs, etc.), see the [RN 0.83 release
notes](https://reactnative.dev/blog/2025/12/10/react-native-0.83).

New for react-native-macos since 0.81:

**Build & distribution**
- feat: add support for dynamic frameworks (#2943)
- feat(macos): migrate init template from Objective-C to Swift (#2948)
- feat(ci): prebuild React xcframework for macOS (#2920)
- feat: build React Native macOS with Swift Package Manager (#2815)

**SwiftUI & RCTUIKit**
- fix(0.83, RCTUIKit): extend support to SwiftUI (#3006)
- fix(0.83, rctuikit): make SwiftUI platform aliases visible to Swift
(#3012)
- fix(macos): include React-RCTUIKit.podspec in package files array
(#2963)

**Fabric / New Architecture on macOS**
- feat: handle right clicks properly (#2885)
- fix(macos): TextInput Fabric commands — setGhostText, blur, and
selection fixes (#2912)
- fix(fabric): textInput text color not adapting to appearance changes
(#2913)
- fix(fabric): multiline text input focus ring and input focus handling
(#2972)
- fix(fabric): force overlay scrollbar style in ScrollView (#2907)
- fix(macos): don't reset prop-derived state during Fabric view recycle
(#3008)
- fix(macos): three Fabric focus regressions — blur,
sendAccessibilityEvent, VirtualView (#3015)
- fix(macos): align TouchableBounce & AccessibilityInfo with upstream
(#3009)
- fix: replace RCTUISecureTextField `#include` hack with proper subclass
(#2895)

**Hermes, autolinking & CI**
- fix(0.83, hermes): resolve hermes from version files instead of
merge-base (#3011)
- chore: support Yarn's pnpm nodeLinker (#3010)
- chore: add support for macos platform key in autolinking config
(#2995)
- fix(codegen): use REACT_NATIVE constant for npmPackageName (#2956)

## Test Plan

CI green: JavaScript Tests (Jest/Flow/ESLint/Prettier), RNTester static
builds (iOS/macOS/visionOS), and Prebuild macOS Core. Full
RNTester-macOS static build also verified locally (`BUILD SUCCEEDED`).