Fix CJS require() returning empty namespace (#89)

Rename CJS bundles to .cjs so Node parses them as CommonJS instead of
treating them as ESM under "type": "module". Bump version to 0.2.8.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: deepentropy

package-lock.json

@@ -1,21 +1,21 @@
 {
   "name": "oakscriptjs",
-  "version": "0.2.7",
+  "version": "0.2.8",
   "type": "module",
   "description": "PineScript v6 compatible technical analysis library for JavaScript/TypeScript",
-  "main": "dist/index.js",
+  "main": "dist/index.cjs",
   "module": "dist/index.mjs",
   "types": "dist/index.d.ts",
   "exports": {
     ".": {
       "types": "./dist/index.d.ts",
       "import": "./dist/index.mjs",
-      "require": "./dist/index.js"
+      "require": "./dist/index.cjs"
     },
     "./runtime": {
       "types": "./dist/runtime/index.d.ts",
       "import": "./dist/runtime/index.mjs",
-      "require": "./dist/runtime/index.js"
+      "require": "./dist/runtime/index.cjs"
     }
   },
   "files": [
@@ -27,9 +27,9 @@
     "prepublishOnly": "npm run build",
     "build": "npm run clean && npm run build:esm && npm run build:cjs && npm run build:runtime:esm && npm run build:runtime:cjs && npm run build:types",
     "build:esm": "esbuild src/index.ts --bundle --format=esm --outfile=dist/index.mjs --platform=neutral --external:@types/* --external:lightweight-charts",
-    "build:cjs": "esbuild src/index.ts --bundle --format=cjs --outfile=dist/index.js --platform=neutral --external:@types/* --external:lightweight-charts",
+    "build:cjs": "esbuild src/index.ts --bundle --format=cjs --outfile=dist/index.cjs --platform=neutral --external:@types/* --external:lightweight-charts",
     "build:runtime:esm": "esbuild src/runtime/index.ts --bundle --format=esm --outfile=dist/runtime/index.mjs --platform=neutral --external:@types/* --external:lightweight-charts",
-    "build:runtime:cjs": "esbuild src/runtime/index.ts --bundle --format=cjs --outfile=dist/runtime/index.js --platform=neutral --external:@types/* --external:lightweight-charts",
+    "build:runtime:cjs": "esbuild src/runtime/index.ts --bundle --format=cjs --outfile=dist/runtime/index.cjs --platform=neutral --external:@types/* --external:lightweight-charts",
     "build:types": "tsc --emitDeclarationOnly --outDir dist",
     "clean": "rimraf dist",
     "dev": "tsc --watch",