feat(analytics): canonical subscription_activated revenue event ()

No PostHog event carried realized revenue, and EFT/havale activations fired
nothing at all — so total paid revenue / MRR was unmeasurable (a Stripe DWH
connector alone would also miss EFT). activateSubscription is the shared
chokepoint for both Stripe (stripe.service) and EFT/manual (billing.service)
activation, so emit one canonical subscription_activated there with PostHog
revenue props: $revenue (major TRY), currency, mrr (yearly amortised /12),
plan, plan_id, brand_count, billing_period, method (looked up from the latest
payment row), referral_credit_days. Funnel steps keep their kuruş 'amount' but
intentionally carry no $revenue, so revenue isn't double-counted.

Unblocks trial->paid, MRR/ARPU and revenue-by-plan/channel across ALL payment
methods. Injected PostHogService (PostHogModule is @Global).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/api/src/subscriptions/subscriptions.service.spec.ts

@@ -56,7 +56,8 @@ function createMockDb(overrides: Record<string, unknown> = {}) {
  * Creates the service with a given mock db injected via reflection.
  */
 function createService(db: unknown): SubscriptionsService {
-  const service = new SubscriptionsService(db as any);
+  const posthog = { captureForUser: vi.fn(), capture: vi.fn() };
+  const service = new SubscriptionsService(db as any, posthog as any);
   return service;
 }
 

apps/api/src/subscriptions/subscriptions.service.ts

@@ -7,11 +7,22 @@ import {
 } from "@nestjs/common";
 import { and, desc, eq, inArray, or } from "drizzle-orm";
 import { DATABASE, type Database } from "../database/database.provider";
-import { brands, plans, userBrands, userSubscriptions, users } from "../database/schema/core";
+import {
+  brands,
+  payments,
+  plans,
+  userBrands,
+  userSubscriptions,
+  users,
+} from "../database/schema/core";
+import { PostHogService } from "../posthog/posthog.service";
 
 @Injectable()
 export class SubscriptionsService {
-  constructor(@Inject(DATABASE) private db: Database) {}
+  constructor(
+    @Inject(DATABASE) private db: Database,
+    private posthog: PostHogService,
+  ) {}
 
   /**
    * Consumes any banked referral reward days for the user (zeroing the balance)
@@ -152,6 +163,35 @@ export class SubscriptionsService {
       }
     }
 
+    // Canonical realized-revenue event. activateSubscription is the shared
+    // chokepoint for BOTH Stripe (stripe.service) and EFT/manual (billing.service)
+    // activation, so total paid revenue becomes measurable in PostHog regardless
+    // of payment method (a Stripe DWH connector alone would miss EFT/havale).
+    // $revenue is in major TRY (PostHog revenue convention); plan prices are kuruş.
+    // This is the single source of $revenue — funnel steps (payment_initiated etc.)
+    // intentionally do NOT carry $revenue so revenue isn't double-counted.
+    const priceKurus =
+      sub.billingPeriod === "yearly" ? (plan[0]?.priceYearly ?? 0) : (plan[0]?.priceMonthly ?? 0);
+    const [lastPayment] = await this.db
+      .select({ method: payments.method })
+      .from(payments)
+      .where(eq(payments.subscriptionId, subscriptionId))
+      .orderBy(desc(payments.createdAt))
+      .limit(1);
+    this.posthog.captureForUser(sub.userId, "subscription_activated", {
+      $revenue: priceKurus / 100,
+      currency: "TRY",
+      amount_kurus: priceKurus,
+      // Normalised monthly recurring revenue (yearly amortised over 12 months).
+      mrr: sub.billingPeriod === "yearly" ? priceKurus / 12 / 100 : priceKurus / 100,
+      plan: plan[0]?.name ?? null,
+      plan_id: sub.planId,
+      brand_count: plan[0]?.brandCount ?? null,
+      billing_period: sub.billingPeriod,
+      method: lastPayment?.method ?? "unknown",
+      referral_credit_days: creditDays,
+    });
+
     return updated;
   }