Switch root tsconfig to moduleResolution: "nodenext"

Enables stricter ESM validation during tsc --noEmit, including
resolution through the package.json exports map. This only applies
to package-name imports (e.g., from '@ably/ai-transport'), not
relative imports - so it doesn't validate our exports today, but
will if we adopt self-referencing imports to fix bundle duplication.

Requires module: "nodenext" to match. Also required adding a
type: "json" import attribute in test/helper/test-setup.ts per
Node.js strict ESM rules.

Author: VeskeR

package.json

@@ -11,26 +11,26 @@
   "sideEffects": false,
   "exports": {
     ".": {
-      "react-native": "./dist/ably-ai-transport.umd.cjs",
       "types": "./dist/index.d.ts",
+      "react-native": "./dist/ably-ai-transport.umd.cjs",
       "import": "./dist/ably-ai-transport.js",
       "require": "./dist/ably-ai-transport.umd.cjs"
     },
     "./react": {
-      "react-native": "./dist/react/ably-ai-transport-react.umd.cjs",
       "types": "./dist/react/index.d.ts",
+      "react-native": "./dist/react/ably-ai-transport-react.umd.cjs",
       "import": "./dist/react/ably-ai-transport-react.js",
       "require": "./dist/react/ably-ai-transport-react.umd.cjs"
     },
     "./vercel": {
-      "react-native": "./dist/vercel/ably-ai-transport-vercel.umd.cjs",
       "types": "./dist/vercel/index.d.ts",
+      "react-native": "./dist/vercel/ably-ai-transport-vercel.umd.cjs",
       "import": "./dist/vercel/ably-ai-transport-vercel.js",
       "require": "./dist/vercel/ably-ai-transport-vercel.umd.cjs"
     },
     "./vercel/react": {
-      "react-native": "./dist/vercel/react/ably-ai-transport-vercel-react.umd.cjs",
       "types": "./dist/vercel/react/index.d.ts",
+      "react-native": "./dist/vercel/react/ably-ai-transport-vercel-react.umd.cjs",
       "import": "./dist/vercel/react/ably-ai-transport-vercel-react.js",
       "require": "./dist/vercel/react/ably-ai-transport-vercel-react.umd.cjs"
     },

test/helper/test-setup.ts

@@ -1,4 +1,4 @@
-import testAppSetup from '../../ably-common/test-resources/test-app-setup.json';
+import testAppSetup from '../../ably-common/test-resources/test-app-setup.json' with { type: 'json' };
 import { isNonSandboxEnvironment } from './environment.js';
 
 // Setup creates a new app in the sandbox environment and sets the key.

tsconfig.json

@@ -18,7 +18,8 @@
     "noImplicitThis": true,
     "esModuleInterop": true,
     "declaration": true,
-    "moduleResolution": "Node",
+    "moduleResolution": "nodenext",
+    "module": "nodenext",
     "skipLibCheck": true,
     "allowJs": true,
     "allowSyntheticDefaultImports": true,