feat(core-shared): scaffold empty package with exports + tags

packages/core-shared/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "@repo/core-shared",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "exports": {
+    ".": "./src/index.ts",
+    "./payload": "./src/payload/index.ts",
+    "./trpc/init": "./src/trpc/init.ts",
+    "./trpc/context": "./src/trpc/context.ts"
+  },
+  "scripts": {
+    "build": "tsc --noEmit",
+    "lint": "eslint .",
+    "test": "vitest run",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "@trpc/server": "^11.0.0",
+    "payload": "^3.14.0",
+    "superjson": "^2.2.1",
+    "zod": "^3.24.0"
+  },
+  "devDependencies": {
+    "@repo/eslint-config": "workspace:*",
+    "@repo/typescript-config": "workspace:*",
+    "@types/node": "^22.0.0",
+    "vitest": "^3.1.0"
+  }
+}