Fix Apple Reject

Add:
- prisma/migrations/20251208042529_add_accepted_terms_at/
- prisma/schema.prisma.backup
- src/app/api/mobile/user/[id]/terms-of-app/

Fix:

prisma/schema.prisma
src/app/api/auth/mobile-register/route.ts
src/app/api/mobile/forum/[id]/report-commentar/route.ts
src/app/api/mobile/forum/[id]/report-posting/route.ts

### No Issue

prisma/migrations/20251208042529_add_accepted_terms_at/migration.sql

@@ -0,0 +1,3 @@
+-- AlterTable
+ALTER TABLE "User" ADD COLUMN     "acceptedForumTermsAt" TIMESTAMP(3),
+ADD COLUMN     "acceptedTermsAt" TIMESTAMP(3);