♻️ refactor: migrate 6 backends to shared-nestjs-metrics

Replace local MetricsService implementations with @manacore/shared-nestjs-metrics:
- chat, calendar, todo, clock, contacts, skilltree

Removes ~350 LOC of duplicated metrics code:
- Delete local metrics directories (service, module, controller)
- Remove manual metrics middleware from main.ts
- Use MetricsModule.register({ prefix: 'app_' }) pattern

Part of consolidation effort - see docs/CONSOLIDATION_OPPORTUNITIES.md

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/skilltree/apps/backend/package.json

@@ -18,6 +18,7 @@
 	},
 	"dependencies": {
 		"@manacore/shared-nestjs-auth": "workspace:*",
+		"@manacore/shared-nestjs-metrics": "workspace:*",
 		"@nestjs/common": "^10.4.9",
 		"@nestjs/config": "^3.3.0",
 		"@nestjs/core": "^10.4.9",

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

@@ -1,8 +1,8 @@
 import { Module } from '@nestjs/common';
 import { ConfigModule } from '@nestjs/config';
+import { MetricsModule } from '@manacore/shared-nestjs-metrics';
 import { DatabaseModule } from './db/database.module';
 import { HealthModule } from './health/health.module';
-import { MetricsModule } from './metrics';
 import { SkillModule } from './skill/skill.module';
 import { ActivityModule } from './activity/activity.module';
 
@@ -12,7 +12,10 @@ import { ActivityModule } from './activity/activity.module';
 			isGlobal: true,
 			envFilePath: '.env',
 		}),
-		MetricsModule,
+		MetricsModule.register({
+			prefix: 'skilltree_',
+			excludePaths: ['/health'],
+		}),
 		DatabaseModule,
 		HealthModule,
 		SkillModule,

apps/skilltree/apps/backend/src/main.ts

@@ -1,49 +1,11 @@
 import { NestFactory } from '@nestjs/core';
 import { ValidationPipe, Logger } from '@nestjs/common';
-import { Request, Response, NextFunction } from 'express';
 import { AppModule } from './app.module';
-import { MetricsService } from './metrics/metrics.service';
-
-// Normalize route paths to prevent high cardinality
-function normalizeRoute(path: string): string {
-	return path
-		.replace(/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/gi, ':id')
-		.replace(/\/\d+/g, '/:id');
-}
 
 async function bootstrap() {
 	const logger = new Logger('Bootstrap');
 	const app = await NestFactory.create(AppModule);
 
-	// Get MetricsService for request tracking
-	const metricsService = app.get(MetricsService);
-
-	// Global Express middleware to track ALL HTTP requests
-	app.use((req: Request, res: Response, next: NextFunction) => {
-		if (req.path === '/metrics') {
-			return next();
-		}
-
-		const startTime = Date.now();
-		const method = req.method;
-		const route = normalizeRoute(req.path);
-
-		res.once('finish', () => {
-			const duration = (Date.now() - startTime) / 1000;
-			metricsService.httpRequestsTotal.inc({
-				method,
-				route,
-				status: res.statusCode.toString(),
-			});
-			metricsService.httpRequestDuration.observe(
-				{ method, route, status: res.statusCode.toString() },
-				duration
-			);
-		});
-
-		next();
-	});
-
 	// Enable CORS
 	app.enableCors({
 		origin: (origin, callback) => {

apps/skilltree/apps/backend/src/metrics/index.ts

@@ -1,3 +0,0 @@
-export * from './metrics.module';
-export * from './metrics.service';
-export * from './metrics.controller';

apps/skilltree/apps/backend/src/metrics/metrics.controller.ts

@@ -1,13 +0,0 @@
-import { Controller, Get, Header } from '@nestjs/common';
-import { MetricsService } from './metrics.service';
-
-@Controller('metrics')
-export class MetricsController {
-	constructor(private metricsService: MetricsService) {}
-
-	@Get()
-	@Header('Content-Type', 'text/plain')
-	async getMetrics(): Promise<string> {
-		return this.metricsService.getMetrics();
-	}
-}

apps/skilltree/apps/backend/src/metrics/metrics.module.ts

@@ -1,11 +0,0 @@
-import { Module, Global } from '@nestjs/common';
-import { MetricsController } from './metrics.controller';
-import { MetricsService } from './metrics.service';
-
-@Global()
-@Module({
-	controllers: [MetricsController],
-	providers: [MetricsService],
-	exports: [MetricsService],
-})
-export class MetricsModule {}

apps/skilltree/apps/backend/src/metrics/metrics.service.ts

@@ -1,37 +0,0 @@
-import { Injectable, OnModuleInit } from '@nestjs/common';
-import { collectDefaultMetrics, Counter, Histogram, Registry } from 'prom-client';
-
-@Injectable()
-export class MetricsService implements OnModuleInit {
-	private registry: Registry;
-
-	public httpRequestsTotal: Counter;
-	public httpRequestDuration: Histogram;
-
-	constructor() {
-		this.registry = new Registry();
-
-		this.httpRequestsTotal = new Counter({
-			name: 'http_requests_total',
-			help: 'Total number of HTTP requests',
-			labelNames: ['method', 'route', 'status'],
-			registers: [this.registry],
-		});
-
-		this.httpRequestDuration = new Histogram({
-			name: 'http_request_duration_seconds',
-			help: 'Duration of HTTP requests in seconds',
-			labelNames: ['method', 'route', 'status'],
-			buckets: [0.01, 0.05, 0.1, 0.5, 1, 2, 5],
-			registers: [this.registry],
-		});
-	}
-
-	onModuleInit() {
-		collectDefaultMetrics({ register: this.registry });
-	}
-
-	async getMetrics(): Promise<string> {
-		return this.registry.metrics();
-	}
-}