Summary

• Prevent repeated Kilo Pass introductory 50% promo claims across accounts by permanently claiming the first positively paid monthly settlement for supported reusable Stripe payment fingerprints (card, sepa_debit, us_bank_account, bacs_debit, and au_becs_debit).
• Persist settlement-derived eligibility reasons and apply an affirmative Stripe promo decision: reused fingerprints, zero-value initial settlements, and unresolved positive settlements cannot receive the introductory promo, while ordinary monthly-ramp behavior remains available.
• Show a customer-safe post-payment warning strictly scoped to the completed Checkout session, and retain only minimal payment-fingerprint anti-abuse evidence through account deletion.
• Define reused-fingerprint Kilo Pass referral disqualification in the governing spec for the not-yet-live Kilo Pass referral processor.

Verification

• No manual browser verification performed in this CLI session; the warning reuses the existing post-Checkout awarding surface and semantic alert primitive.

Visual Changes

N/A - adds an existing-style warning alert on the post-payment awarding screen when the introductory offer is unavailable.

Reviewer Notes

• Annual subscriptions remain unaffected by the reusable-payment-fingerprint rule.
• A confirmed settled payment method without a supported reusable fingerprint may still use existing account-history eligibility; unresolved positive Stripe settlements fail closed for the introductory promo.
• Invoice settlement supports both PaymentIntent and direct Charge payment representations.
• The final branch diff contains one generated Drizzle migration for this feature; earlier branch-local intermediate migrations were dropped and regenerated via drizzle-kit.
• Kilo Pass referral conversion/reward processing is schema/spec-prepared but not currently implemented in application logic; the persisted reason is available for that future integration.