fix: add try-catch to all OnModuleInit hooks to prevent startup crashes

- PrismaService.onModuleInit: catch DB connection failures
- CostAggregationService.onModuleInit: catch aggregation errors
- MetricsCleanupService.onModuleInit: catch cleanup errors

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/infrastructure/database/prisma.service.ts

@@ -1,4 +1,4 @@
-import { Injectable, OnModuleInit, OnModuleDestroy } from '@nestjs/common';
+import { Injectable, OnModuleInit, OnModuleDestroy, Logger } from '@nestjs/common';
 import { PrismaClient } from '@prisma/client';
 
 @Injectable()
@@ -6,8 +6,15 @@ export class PrismaService
   extends PrismaClient
   implements OnModuleInit, OnModuleDestroy
 {
+  private readonly logger = new Logger(PrismaService.name);
+
   async onModuleInit() {
+    try {
       await this.$connect();
+      this.logger.log('Database connected');
+    } catch (err: any) {
+      this.logger.error(`Database connection failed: ${err.message}`);
+    }
   }
 
   async onModuleDestroy() {

src/modules/admin-costs/cost-aggregation.service.ts

@@ -11,7 +11,11 @@ export class CostAggregationService implements OnModuleInit, OnModuleDestroy {
   constructor(private readonly prisma: PrismaService) {}
 
   async onModuleInit() {
+    try {
       await this.aggregateToday();
+    } catch (err: any) {
+      this.logger.warn(`Initial cost aggregation failed: ${err.message}`);
+    }
     this.timer = setInterval(() => this.aggregateToday(), AGGREGATE_INTERVAL_MS);
   }
 

src/modules/admin-metrics/metrics-cleanup.service.ts

@@ -12,8 +12,8 @@ export class MetricsCleanupService implements OnModuleInit, OnModuleDestroy {
   constructor(private readonly prisma: PrismaService) {}
 
   async onModuleInit() {
-    await this.cleanup();
-    this.timer = setInterval(() => this.cleanup(), CLEANUP_INTERVAL_MS);
+    await this.cleanup().catch(() => {});
+    this.timer = setInterval(() => this.cleanup().catch(() => {}), CLEANUP_INTERVAL_MS);
   }
 
   onModuleDestroy() {