Seven Day Free Trial + Subscribe Funnel Fixes

[vishakh]

Free trial (Stripe card only)

• Stripe subscriptions now include a 7-day trial period. Card details are collected upfront via SetupIntent; no charge until day 8.
• Trial access is gated on default_payment_method being set — abandoning the form before submitting card details grants no access.
• Trialing subscriptions are now included in cancellation (cancelled immediately, since no charge has occurred). Previously the cancel endpoint only queried active status, so trial users could not cancel before billing started.
• subscription-manager.ts uses trial_end as the expiry date for trialing subscriptions.

Auth credential lookup fix

• verifiedCredentials?.[0]?.address replaced with verifiedCredentials?.find((c) => c.address)?.address throughout AuthProvider, subscribe/page, and PremiumFeatureHeader. Users who sign in via email/social (where the wallet credential is not at index 0) were hitting the "Connect a wallet" gate on the subscribe page even though Dynamic had created an embedded wallet for them.

Subscribe copy

• All paywall surfaces updated to surface the free trial: gate banners, payment modal, Stripe form, subscribe page, and layout metadata.

Analytics

• payment_method_selected added to GA event tracking (was firing in code but not queried).
• New fetchSubscribeFunnel query in the analysis script tracks subscribe_page_viewed → payment_method_selected → checkout_started as a dedicated funnel section.
• Removed misleading "by auth state" label from the subscribe funnel output (the query does not include a state dimension).