feat(core-analytics): add React provider and useAnalytics hook

Adds a ./react subpath export to @repo/core-analytics containing
<AnalyticsProvider value={IAnalytics}> and useAnalytics(): IAnalytics.
useAnalytics() throws AnalyticsContextError when called outside a provider.
React Testing Library test verifies track() flows through context using
RecordingAnalytics. Switches vitest config to pick up .tsx test files
via environmentMatchGlobs and extends tsconfig to react-library.json
for JSX support.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/core-analytics/package.json

@@ -4,7 +4,8 @@
   "private": true,
   "type": "module",
   "exports": {
-    ".": "./src/index.ts"
+    ".": "./src/index.ts",
+    "./react": "./src/react/index.ts"
   },
   "scripts": {
     "build": "tsc --noEmit",
@@ -12,6 +13,14 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run --passWithNoTests"
   },
+  "peerDependencies": {
+    "react": "^18.0.0 || ^19.0.0"
+  },
+  "peerDependenciesMeta": {
+    "react": {
+      "optional": true
+    }
+  },
   "dependencies": {
     "@repo/core-shared": "workspace:*"
   },
@@ -19,7 +28,11 @@
     "@repo/core-eslint": "workspace:*",
     "@repo/core-testing": "workspace:*",
     "@repo/core-typescript": "workspace:*",
+    "@testing-library/react": "^16.0.0",
+    "@types/react": "^19.0.0",
     "@vitest/coverage-v8": "^3.0.0",
+    "jsdom": "^25.0.0",
+    "react": "^19.0.0",
     "typescript": "^5.8.0",
     "vitest": "^3.0.0"
   }