Fix ES module/CommonJS mismatch in shared package

- Rename CommonJS build output from .js to .cjs extensions
- Add .js extensions to ESM imports (required by Node.js)
- Add .cjs extensions to CommonJS requires
- Add post-build scripts for both ESM and CommonJS builds
- Update package.json exports to reference .cjs files for require()

Fixes: ReferenceError: exports is not defined in ES module scope

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

shared/package.json

@@ -5,8 +5,8 @@
   "type": "module",
   "scripts": {
     "prebuild": "barrelsby --directory src --delete --single",
-    "build:esm": "tsc -p tsconfig.esm.json",
-    "build:cjs": "tsc -p tsconfig.cjs.json",
+    "build:esm": "tsc -p tsconfig.esm.json && node scripts/postbuild-esm.cjs",
+    "build:cjs": "tsc -p tsconfig.cjs.json && find dist/cjs -name \"*.js\" -type f -exec sh -c 'mv \"$1\" \"${1%.js}.cjs\"' _ {} \\; && node scripts/postbuild.cjs",
     "build": "npm run prebuild && npm run build:esm && npm run build:cjs",
     "lint": "eslint ."
   },
@@ -14,7 +14,7 @@
     ".": {
       "types": "./dist/types/index.d.ts",
       "import": "./dist/esm/index.js",
-      "require": "./dist/cjs/index.js"
+      "require": "./dist/cjs/index.cjs"
     }
   },
   "types": "./dist/types/index.d.ts",