feat(billing): scaffold dual Stripe account support (EE default)

[riderx]

Summary (AI generated)

• Add billing_account (ee | us) on stripe_info, default/backfill ee for all existing rows.
• Add nullable US catalog columns on plans (stripe_id_us, price_m_id_us, price_y_id_us, credit_id_us) — left empty.
• Introduce stripe_billing_account.ts with getStripe(c, account), resolveBillingAccount, and getNewCustomersBillingAccount (defaults to EE; US only when US secrets exist).
• EE keeps STRIPE_SECRET_KEY + STRIPE_WEBHOOK_SECRET; optional STRIPE_SECRET_KEY_US + STRIPE_WEBHOOK_SECRET_US (US client fails closed if missing).
• Add /triggers/stripe_event_us webhook route; stamp billing_account on processed_stripe_events (composite PK).
• New org Stripe provisioning stores billing_account from STRIPE_NEW_CUSTOMERS_ACCOUNT (safe default EE).
• Unit tests for account resolution and EE-only operation without US secrets.

Motivation (AI generated)

Capgo will eventually bill new customers on a US Stripe account while existing customers remain on the Estonian account. This PR adds the data model, env wiring, and client routing scaffolding without routing live traffic to US.

Business Impact (AI generated)

Enables a future US billing cutover without migrating existing cus_ / sub_ IDs. No customer-facing billing change in this PR: all orgs stay on EE until US secrets and operational flag flip (out of scope here).

Test Plan (AI generated)

• tests/stripe-billing-account.unit.test.ts — EE default, US fail-closed, US client when billing_account=us + US key
• tests/stripe-redirects.unit.test.ts — checkout/portal/customer updates with EE-only secrets
• tests/stripe-subscription-events.unit.test.ts, tests/stripe-revenue-movement.unit.test.ts, tests/plans-billing-history.unit.test.ts
• bun run typecheck:backend (pre-commit)
• CI backend/integration Stripe tests

Generated with AI

  

---

^{Need help on this PR? Tag @codesmith-bot with what you need. Autofix is disabled.}

[coderabbitai]

Important

Draft PR not reviewed

Draft PRs are not automatically reviewed by default.

• Trigger a manual review

To automatically review draft PRs, update your CodeRabbit configuration:

reviews:
  auto_review:
    drafts: true

---

_{Comment @coderabbitai help to get the list of available commands.}

[codspeed-hq]

Merging this PR will not alter performance

✅ 43 untouched benchmarks
⏩ 2 skipped benchmarks¹

---

_{Comparing cursor/dual-stripe-account-scaffolding-7cf6 (4320fdc) with main (c703c09)}

Footnotes

1. 2 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud