chore(deps): pin tsx 4.23.13 and add migrate:content script

tsx 4.22.4 (the version resolved before this was an explicit
dependency) fails on Node v25.6.1 with "T.registerHooks is not a
function" — its CommonJS-require hook feature-detection finds
node:module's registerHooks but calls it with a shape that version of
Node no longer accepts. This broke both the `payload` CLI (needed for
`generate:importmap`, see next commit) and would have broken
`npm run migrate:content` (MITHOME-87) the same way. 4.23.13 fixes it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

proto/package.json

@@ -27,7 +27,8 @@
     "docker:dev:down": "cd .. && docker-compose -f docker-compose.dev.yml down",
     "docker:dev:logs": "cd .. && docker-compose -f docker-compose.dev.yml logs -f app",
     "docker:build": "docker build -t mozdit-app .",
-    "docker:run": "docker run -p 3000:3000 --env-file .env.local mozdit-app"
+    "docker:run": "docker run -p 3000:3000 --env-file .env.local mozdit-app",
+    "migrate:content": "node --env-file=.env.local --import tsx scripts/migrate-content-to-payload.ts"
   },
   "dependencies": {
     "@payloadcms/db-mongodb": "^3.88.0",
@@ -59,6 +60,7 @@
     "jest": "^29.7",
     "jest-environment-jsdom": "^29.7",
     "tailwindcss": "^4",
+    "tsx": "^4.23.13",
     "typescript": "^5",
     "undici": "^7.15.0",
     "winston": "^3.11",