Add the MIT license

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

package.json

@@ -2,6 +2,7 @@
   "name": "mangacircus",
   "version": "1.0.0",
   "private": true,
+  "license": "MIT",
   "description": "No-frills self-hosted manga reader with no runtime dependencies.",
   "main": "server.js",
   "scripts": {