fix(typescript-config): expose nextjs.json + react-library.json in exports map

The prior commit added an exports map that only listed base.json and
vitest.base, accidentally hiding nextjs.json and react-library.json
from packages that extend them via tsconfig.json. Adds them back.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/typescript-config/package.json

@@ -5,6 +5,8 @@
   "type": "module",
   "exports": {
     "./base.json": "./base.json",
+    "./nextjs.json": "./nextjs.json",
+    "./react-library.json": "./react-library.json",
     "./vitest.base": "./vitest.base.ts"
   },
   "devDependencies": {