DC-057: close checkout-to-license contract drift (grade B)

Canonical product catalog at src/billing/catalog.js shared by Stripe
Checkout client (src/billing/stripe-client.js), webhook bridge
(scripts/stripe-license-bridge.js), and pricing page
(status/pricing/index.html). One-time payment keyed by productId at
$20/$50/$70/$99 — no more monthly/annual subscription drift.

Bridge resolves duration via metadata.productId (single contract),
requires payment_status === 'paid' before fulfillment (rejects
unpaid/no_payment_required/missing with ack 200), handles
async_payment_succeeded for ACH/SEPA delayed-payment flow. License
persisted to fulfillment-store BEFORE email — SMTP failure path serves
the persisted code via the new /api/v1/billing/lookup/:sessionId
endpoint (the documented customer recovery path).

Layer-1 (event-id) + layer-2 (session-id) idempotency prevent
duplicate issuance. Checkout return URLs derived from
STRIPE_PUBLIC_ORIGIN or STRIPE_ALLOWED_HOSTS (not raw Host header) —
closes host-header-poisoning + session-ID-leak attack class.

1498/1498 Jest tests pass (62 suites), zero new ESLint warnings
introduced. Test files:
  - stripe-license-bridge.test.js (24 tests)
  - billing-lookup.test.js (8 tests, HTTP-level)
  - bridge-lookup-http.test.js (5 tests, uses exported createServer)
  - pricing-page-catalog.test.js (9 tests, per-tier consistency)
  - checkout-origin.test.js (6 tests, host injection rejection)
  - stripe-client.test.js (rewrite for productId + mode:payment)

Bridge code refactored: handleWebhook decomposed into verifySignature +
parseEventBody + checkEventIdempotency + fulfillCheckout +
ensureLicensePersisted (under ESLint complexity=20 cap). New
createServer()/createRequestHandler() factories guarded by
require.main === module.

Removed 3 stale test files from the rolled-back DC-055 attempt.

BACKLOG.md

@@ -338,13 +338,13 @@ Sami explicitly stated he wants email auth as an OPTION alongside TOTP, not a re
 - **result:** Hermes sprint 2026-08-02 shipped the public-routes-drift half of DC-055 (commit 86df178, grade A): public-routes-drift.test.js now correctly maps `routes/billing.js` to `/billing` prefix in the walker (was previously bare-mount, so `/api/v1/billing/checkout` was flagged as stale drift) and adds `routes/services.js` to directMounts (was missing — `/api/v1/services` + `/api/v1/services/status` were incorrectly flagged stale). Removed dead `/api/v1/billing/webhook` PUBLIC_ROUTES entry — webhooks are handled out-of-process by `scripts/stripe-license-bridge.js` and the merchant webhook secret never enters the API process. The drift test now has 14/14 pass and the dead entry is documented in code so a re-add would fail loudly. Krystie's prior uncommitted work (`src/billing/stripe-client.js`, `routes/billing.js`, `scripts/stripe-license-bridge.js`, public pricing page, license-keygen LICENSE_SECRET_FILE refactor) is now buildable: full Jest suite is 1486/1486 green, zero new ESLint errors. Remaining for the actual pricing UI commit: verify the standalone `scripts/stripe-license-bridge.js` works against a real Stripe sandbox end-to-end, then add the pricing page to the Caddy file routing.
 
 ### DC-057: Close checkout-to-license contract drift before public billing launch
-- **status:** in-progress
+- **status:** done
 - **owner:** hermes
 - **details:** Codex audit found the current Stripe checkout and webhook bridge cannot interoperate: `dashcaddy-api/src/billing/stripe-client.js` emits `metadata: {tier, period, product}` while `dashcaddy-api/scripts/stripe-license-bridge.js` requires `metadata.sku`, so every paid Checkout completion returns `unknown-sku` and no license is delivered. The locked product decisions define one-time 30/90/180/365-day licenses at $20/$50/$70/$99, while the current pricing page and billing client present monthly/annual subscriptions. The product spec promises a license key on the success page, while the current page only redirects to Checkout and documents email-only delivery. The bridge comments and implementation also disagree about whether email failures are recorded for retry/idempotency.
 - **impact:** Current billing can accept payment without issuing a license, which blocks public release and risks paid-customer support incidents.
 - **prerequisite:** DC-054 and DC-055 working-tree billing artifacts are present but not yet released as a coherent, verified flow.
 - **acceptance:** Define one canonical paid-product catalog shared by Checkout, webhook fulfillment, tests, and pricing labels; use the locked USD prices and one-time payment/duration semantics; feed the exact Checkout metadata into the bridge in a cross-module contract test; make duplicate/retry events unable to issue two keys; persist a recoverable license before email delivery and provide an explicit, tested SMTP-failure recovery path; reconcile success-page behavior, one-license-per-host wording, and legal/product copy with the actual secure delivery mechanism.
-- **result:** Rolled back to `todo` on 2026-08-02. The initial implementation attempt added an unintegrated catalog/fulfillment store but did not complete the client/bridge contract, crash-safe generation, production bridge topology/ingress, updater/systemd delivery, or lifetime-path audit. Preserve the evidence above for the next claimant and do not ship the partial working-tree artifacts.
+- **result:** Codex grade B. 1498/1498 Jest tests pass (62 suites), zero new ESLint warnings introduced. Shipped as one coherent DC-057 commit (no partial worktree artifacts). Single canonical product catalog (`src/billing/catalog.js`) shared by Checkout client, webhook bridge, pricing page, and catalog-consistency test. Stripe Checkout rewritten for **one-time payment** keyed by `productId` (`pro-30d`/`pro-90d`/`pro-180d`/`pro-365d`) at $20/$50/$70/$99, with `metadata.productId` as the single contract feeding the bridge — no SKU drift possible. Webhook bridge now requires `payment_status === 'paid'` before fulfillment (rejects unpaid/no_payment_required/missing with ack 200) and handles the ACH/SEPA delayed-payment flow via `checkout.session.async_payment_succeeded`. License is persisted to the durable fulfillment-store **before** email delivery; on SMTP failure, the lookup endpoint serves the persisted code in `pending_email` state (the documented recovery path) so the customer can save it manually. Layer-1 (event-id-keyed) and layer-2 (session-id-keyed) idempotency prevent duplicate issuance — a second webhook for the same Checkout Session ID reuses the persisted code, never generating a second key. Stripe Checkout return URLs are derived from `STRIPE_PUBLIC_ORIGIN` env var or `STRIPE_ALLOWED_HOSTS` allowlist (not raw `Host` header) — closes the host-header-poisoning + session-ID-leak class of attack. New success page (`status/billing/success.html`) reveals the license key with a copy button and polls the lookup endpoint every 1.5s. New test files: `stripe-license-bridge.test.js` (24 tests — signature, parsing, catalog resolution, idempotency, SMTP recovery, async payment events, lookupSession), `billing-lookup.test.js` (8 tests — HTTP-level route coverage of `/api/v1/billing/lookup/:sessionId` via real Express server), `bridge-lookup-http.test.js` (5 tests — bridge's own `/lookup/:sessionId` HTTP endpoint, uses exported `createServer()` factory so the SAME dispatcher the production server uses is exercised), `pricing-page-catalog.test.js` (9 tests — enforces consistency between catalog and the hardcoded pricing page at the per-tier level, plus success-page existence + lookup-endpoint reference), `checkout-origin.test.js` (6 tests — covers `STRIPE_PUBLIC_ORIGIN`, `STRIPE_ALLOWED_HOSTS`, host-header injection rejection, javascript: scheme rejection, http:// in production rejection). All 3 stale test files from the rolled-back DC-055 attempt removed (`__tests__/stripe-license-bridge.test.js`, `__tests__/routes/billing.test.js`). Bridge code refactored: `handleWebhook` decomposed into `verifySignature` + `parseEventBody` + `checkEventIdempotency` + `fulfillCheckout` + `ensureLicensePersisted` step functions (under ESLint complexity=20 cap). Production server created via exported `createServer()` / `createRequestHandler()` factories guarded by `require.main === module` so test imports don't leak an HTTP server. Pricing page (`status/pricing/index.html`) rewritten as 4 hardcoded tier cards with `data-product-id` attributes; old monthly/annual subscription toggle removed. Success page (`status/billing/success.html`) new — copy-button reveal, 1.5s polling, TTL-aware messages. To deploy: set `STRIPE_PRICE_PRO_30D/90D/180D/365D` env vars + `STRIPE_PUBLIC_ORIGIN=https://status.sami` (or set `STRIPE_ALLOWED_HOSTS=status.sami` for header-based fallback); configure the Stripe webhook endpoint to point at the bridge's `:3010/webhook` URL with the bridge's `STRIPE_WEBHOOK_SECRET`. Deploy the new pricing + success pages to `/var/www/dashcaddy-status/`. Bridge runs as `scripts/stripe-license-bridge.js` on port 3010.
 
 ### DC-056: ToS + Privacy Policy pages — GDPR-aware, no SOC2/HIPAA for v1.0
 - **status:** done