fix: upgrade calendar jest to v30 and add rate limiting to contacts/todo backends

- Calendar backend: upgrade jest 29→30 to fix broken pnpm symlink
  (jest 29 wasn't resolving in pnpm store, all 63 tests now pass)
- Contacts backend: add @nestjs/throttler (100 req/min)
- Todo backend: add @nestjs/throttler (100 req/min)
- Consistent rate limiting across all three backends (calendar already had it)

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

apps/todo/apps/backend/package.json

@@ -28,16 +28,17 @@
 		"@nestjs/core": "^10.4.9",
 		"@nestjs/platform-express": "^10.4.9",
 		"@nestjs/schedule": "^4.1.2",
+		"@nestjs/throttler": "^6.2.1",
 		"@todo/shared": "workspace:*",
 		"class-transformer": "^0.5.1",
 		"class-validator": "^0.14.1",
 		"dotenv": "^16.4.7",
 		"drizzle-orm": "^0.38.3",
 		"postgres": "^3.4.5",
+		"prom-client": "^15.1.0",
 		"reflect-metadata": "^0.2.2",
 		"rrule": "^2.8.1",
-		"rxjs": "^7.8.1",
-		"prom-client": "^15.1.0"
+		"rxjs": "^7.8.1"
 	},
 	"devDependencies": {
 		"@nestjs/cli": "^10.4.9",

apps/todo/apps/backend/src/app.module.ts

@@ -1,6 +1,7 @@
 import { Module } from '@nestjs/common';
 import { ConfigModule, ConfigService } from '@nestjs/config';
 import { ScheduleModule } from '@nestjs/schedule';
+import { ThrottlerModule } from '@nestjs/throttler';
 import { MetricsModule } from '@manacore/shared-nestjs-metrics';
 import { ManaCoreModule } from '@manacore/nestjs-integration';
 import { DatabaseModule } from './db/database.module';
@@ -20,6 +21,12 @@ import { AdminModule } from './admin/admin.module';
 			envFilePath: '.env',
 		}),
 		ScheduleModule.forRoot(),
+		ThrottlerModule.forRoot([
+			{
+				ttl: 60000, // 60 seconds
+				limit: 100, // 100 requests per minute
+			},
+		]),
 		MetricsModule.register({
 			prefix: 'todo_',
 			excludePaths: ['/health'],