feat: add PostHog analytics to frontend

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

Author: gugu

frontend/package.json

@@ -57,6 +57,7 @@
 		"ngx-stripe": "^19.0.0",
 		"pluralize": "^8.0.0",
 		"postgres-interval": "^4.0.2",
+		"posthog-js": "^1.341.0",
 		"private-ip": "^3.0.2",
 		"puppeteer": "^24.29.1",
 		"rxjs": "^7.4.0",

frontend/src/main.ts

@@ -16,6 +16,7 @@ import { provideCharts, withDefaultRegisterables } from 'ng2-charts';
 import { CookieService } from 'ngx-cookie-service';
 import { MarkdownModule, provideMarkdown } from 'ngx-markdown';
 import { NgxStripeModule } from 'ngx-stripe';
+import posthog from 'posthog-js';
 import { AppComponent } from './app/app.component';
 import { AppRoutingModule } from './app/app-routing.module';
 import { ConfigModule } from './app/modules/config.module';
@@ -83,6 +84,11 @@ if ((environment as any).saas) {
 	});
 }
 
+posthog.init('phc_VPnWHIMj9UjhRLPr7shATjgL0J4KrWWOHkK3JwZbnkw', {
+	api_host: 'https://us.i.posthog.com',
+	defaults: '2025-11-30',
+});
+
 bootstrapApplication(AppComponent, {
 	providers: [
 		importProvidersFrom(