refactor: rename package scope from @sexy.pivoine.art to @sexy

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

packages/backend/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "@sexy.pivoine.art/backend",
+  "name": "@sexy/backend",
   "version": "1.0.0",
   "private": true,
   "scripts": {
@@ -20,8 +20,8 @@
     "@fastify/static": "^8.1.1",
     "@pothos/core": "^4.4.0",
     "@pothos/plugin-errors": "^4.2.0",
-    "@sexy.pivoine.art/email": "workspace:*",
-    "@sexy.pivoine.art/types": "workspace:*",
+    "@sexy/email": "workspace:*",
+    "@sexy/types": "workspace:*",
     "argon2": "^0.43.0",
     "bullmq": "^5.70.4",
     "drizzle-orm": "^0.44.1",