fix: replace require('qrcode') with await import() for ESM compatibility

require() is not defined in ESM modules. The production build (tsc)
outputs ESM, causing 'require is not defined' → 500 → 'QR unavailable'.
Vitest/tsx shimmed require() so tests passed but production was broken.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -51,6 +51,7 @@
     "@fastify/compress": "^8.3.1",
     "@fastify/cookie": "^11.0.2",
     "@fastify/static": "^8.0.0",
+    "@rollup/rollup-linux-x64-gnu": "^4.59.0",
     "chalk": "^5.3.0",
     "chokidar": "^3.6.0",
     "commander": "^12.1.0",
@@ -72,6 +73,7 @@
     "@remotion/transitions": "4.0.429",
     "@types/node": "^20.19.33",
     "@types/pngjs": "^6.0.5",
+    "@types/qrcode": "^1.5.6",
     "@types/react": "^19.2.14",
     "@types/uuid": "^10.0.0",
     "@types/web-push": "^3.6.4",