fix(analytics): move middleware after pre-parser routes and decouple billing events

- Analytics middleware now mounts after initPreParserRoutes so webhooks
  and other pre-parser endpoints are not tracked (fixes overhead/noise).
- Billing plan-change listener moved to modules/billing/billing.init.js
  to eliminate the lib→module dependency (correct direction: module→lib).
- Added JSDoc to the init function.

Author: PierreBrisorgueil

lib/services/express.js

@@ -23,7 +23,6 @@ import requestId from '../middlewares/requestId.js';
 import sentry from './sentry.js';
 import AnalyticsService from './analytics.js';
 import analyticsMiddleware from '../middlewares/analytics.js';
-import billingEvents from '../../modules/billing/lib/events.js';
 
 /**
  * Initialize Swagger
@@ -206,7 +205,9 @@ const initErrorRoutes = (app) => {
 };
 
 /**
- * Initialize the Express application
+ * Initialize the Express application.
+ *
+ * @returns {Promise<import('express').Express>} Configured Express app
  */
 const init = async () => {
   // Initialize express app
@@ -217,17 +218,12 @@ const init = async () => {
   initLocalVariables(app);
   // Assign a unique request ID before any route registration
   app.use(requestId);
+  // Initialize pre-parser routes (before body parsing, CSRF, and analytics)
+  await initPreParserRoutes(app);
   // Initialize analytics (PostHog) and mount auto-capture middleware
+  // Mounted after pre-parser routes so webhooks are not tracked
   await AnalyticsService.init();
   app.use(analyticsMiddleware);
-  // Listen for billing plan changes and update group properties
-  billingEvents.on('plan.changed', ({ organizationId, newPlan }) => {
-    try {
-      AnalyticsService.groupIdentify('company', String(organizationId), { plan: newPlan });
-    } catch (_) { /* analytics must not break billing flow */ }
-  });
-  // Initialize pre-parser routes (before body parsing and CSRF)
-  await initPreParserRoutes(app);
   // Initialize Express middleware
   initMiddleware(app);
   // Initialize Helmet security headers

modules/billing/billing.init.js

@@ -0,0 +1,19 @@
+/**
+ * Module dependencies
+ */
+import AnalyticsService from '../../lib/services/analytics.js';
+import billingEvents from './lib/events.js';
+
+/**
+ * Billing module initialisation.
+ * Wires cross-module integrations that depend on services from lib.
+ */
+// eslint-disable-next-line no-unused-vars
+export default async (app) => {
+  // Update analytics group properties when a subscription plan changes
+  billingEvents.on('plan.changed', ({ organizationId, newPlan }) => {
+    try {
+      AnalyticsService.groupIdentify('company', String(organizationId), { plan: newPlan });
+    } catch (_) { /* analytics must not break billing flow */ }
+  });
+};