feat(analytics): send PostHog event for analytics opt-in choice (#296)

Capture an analytics_opt_in event when users choose to opt in or out
of analytics during onboarding. The event bypasses the analytics
enabled check so we can measure opt-in rates from both choices.

Author: theFong

pkg/analytics/posthog.go

@@ -94,6 +94,30 @@ func GetOrCreateAnalyticsID() string {
 	return settings.AnalyticsID
 }
 
+// CaptureAnalyticsOptIn sends an event recording the user's analytics consent choice.
+// This is sent regardless of the user's choice so we can measure opt-in rates.
+func CaptureAnalyticsOptIn(optedIn bool) {
+	anonID := GetOrCreateAnalyticsID()
+	if anonID == "" {
+		return
+	}
+
+	c, err := getClient()
+	if err != nil {
+		return
+	}
+
+	_ = c.Enqueue(posthog.Capture{
+		DistinctId: anonID,
+		Event:      "analytics_opt_in",
+		Properties: posthog.NewProperties().
+			Set("opted_in", optedIn).
+			Set("os", runtime.GOOS).
+			Set("arch", runtime.GOARCH).
+			Set("cli_version", version.Version),
+	})
+}
+
 // IdentifyUser links the anonymous analytics ID to a real user ID using PostHog Alias.
 func IdentifyUser(userID string) {
 	enabled, asked := IsAnalyticsEnabled()

pkg/cmd/login/login.go

@@ -241,6 +241,7 @@ func (o LoginOptions) handleOnboarding(user *entity.User, _ *terminal.Terminal)
 		})
 		optIn := strings.HasPrefix(choice, "Yes")
 		_ = analytics.SetAnalyticsPreference(optIn)
+		analytics.CaptureAnalyticsOptIn(optIn)
 	}
 
 	analytics.IdentifyUser(user.ID)