Phase 1: vendor static_h Hermes, bump to RN 0.87 nightly

Begin migrating off the kraenhansen/hermes fork + JSI-patching path toward
Hermes' first-party Node-API (the static_h branch).

- vendor-hermes: shallow-fetch facebook/hermes at pinned static_h SHA
  0ae42446d1ae669508368b0a18e60c789f76735d; drop the JSI-header copy step
- patch-hermes.rb: rely on REACT_NATIVE_OVERRIDE_HERMES_DIR alone to trigger
  build-from-source; drop the no-op BUILD_FROM_SOURCE var and the obsolete
  RCT_USE_PREBUILT_RNCORE / JSI-patch guard
- CxxNodeApiHostModule: stub env=nullptr (real env arrives in Phase 2 via
  hermes_napi_create_env)
- bump react-native to 0.87.0-nightly-20260529-88857d22f (+ test-app deps,
  react-native-test-app 5.x); regenerate lockfile
- RN 0.87 fallout: add @types/babel__core, fix test-app tsconfig extends for
  the tightened @react-native/typescript-config exports map, delete the
  podspec test asserting the removed guard

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: kraenhansen

apps/test-app/package.json

@@ -30,20 +30,20 @@
     "@react-native-node-api/ferric-example": "*",
     "@react-native-node-api/node-addon-examples": "*",
     "@react-native-node-api/node-tests": "*",
-    "@react-native/babel-preset": "0.81.4",
-    "@react-native/metro-config": "0.81.4",
-    "@react-native/typescript-config": "0.81.4",
+    "@react-native/babel-preset": "0.87.0-nightly-20260529-88857d22f",
+    "@react-native/metro-config": "0.87.0-nightly-20260529-88857d22f",
+    "@react-native/typescript-config": "0.87.0-nightly-20260529-88857d22f",
     "@rnx-kit/metro-config": "^2.1.1",
     "@types/mocha": "^10.0.10",
     "@types/react": "^19.1.0",
     "concurrently": "^9.1.2",
     "mocha": "^11.6.0",
     "mocha-remote-cli": "^1.13.2",
     "mocha-remote-react-native": "^1.13.2",
-    "react": "19.1.0",
-    "react-native": "0.81.4",
+    "react": "19.2.3",
+    "react-native": "0.87.0-nightly-20260529-88857d22f",
     "react-native-node-api": "*",
-    "react-native-test-app": "^4.4.7",
+    "react-native-test-app": "^5.1.9",
     "weak-node-api": "*"
   }
 }

apps/test-app/tsconfig.json

@@ -1,5 +1,5 @@
 {
-  "extends": "@react-native/typescript-config/tsconfig.json",
+  "extends": "@react-native/typescript-config",
   "compilerOptions": {
     "types": ["react-native", "mocha"]
   },