chore: Upgrade Apollo Server from v4 to v5

Updated packages:
- @apollo/server: 4.12.2 → 5.0.0

Testing Results:
✅ TypeScript compilation: 0 errors
✅ Server running correctly
✅ All endpoints responding

🤖 Generated with Claude Code

maternal-app/maternal-app-backend/package.json

@@ -21,7 +21,7 @@
     "migration:run": "ts-node src/database/migrations/run-migrations.ts"
   },
   "dependencies": {
-    "@apollo/server": "^4.12.2",
+    "@apollo/server": "^5.0.0",
     "@aws-sdk/client-s3": "^3.899.0",
     "@aws-sdk/lib-storage": "^3.900.0",
     "@aws-sdk/s3-request-presigner": "^3.899.0",