Railway deploy blocked: 11 Stripe billing tests fail in server/ on CI

[masonwyatt23]

Symptom

deploy-server.yml is blocked on every push to main because the Run tests gate fails. The deploy step never runs, so the Railway server has not received a deploy in this pipeline since at least 2026-05-15 (commit 90df5772).

Confirmed pre-existing — NOT caused by PR #66 (v1.31 Phase 0) or PR #67 (Q1 Genome 2.0 + WAD-D). Same deploy failed identically on 90df5772 before either landed.

Reproduction

cd server && bun test

11 failures, all in billing tests:

Route	Failing tests
`POST /billing/checkout`	4
`GET /billing/portal`	1
`POST /billing/webhook`	6

All share the same error:

TypeError: undefined is not an object (evaluating 'stripe.checkout.sessions')

Root cause (per the fix in #68)

The Stripe SDK constructed with a stub key lazily resolves resource attributes — `stripe.checkout`, `stripe.webhooks`, `stripe.billingPortal` come back as `undefined` on the CI bun runtime (1.3.14) but are fully populated on the local bun (1.3.13). A neighboring test (`admin-user-detail.test.ts`) already uses `mock.module("../src/lib/stripe.js", ...)` to side-step this; when both files share a process the side-effect leaks and makes `billing.test.ts` accidentally green locally. CI ran `billing.test.ts` early enough that the leak hadn't occurred, so the 11 calls against `stripe.checkout.sessions` / `stripe.webhooks.constructEvent` threw.

Fix shipped in #68

Option A from the issue plan: a test-setup module mock at the top of `server/tests/billing.test.ts` that calls `mock.module("../src/lib/stripe.js", ...)` before importing the app. Zero production code changed.

Impact (now resolving)

• Railway server has not received a deploy since at least 2026-05-15.
• Existing prod instance is still running on the last successful deploy — no data loss, no outage.
• Q1 WAD-D backend endpoint + migrations (`POST /stats/daily-active`, `daily_active_records`, `wad_d_snapshots`) merged in PR Phase 1 Q1 — Genome 2.0 MVP + WAD-D instrumentation (client + backend) #67 are not yet deployed. Will deploy once fix(server): mock Stripe SDK module in billing tests to unblock Railway deploy #68 lands.
• v1.31 Phase 0 (PR Ship v1.31 Phase 0 — $0 fix + SessionEnd nudges + onboarding hero #66) deploy was unaffected — that release didn't touch `server/`.

Failing run IDs

• `26318429492` — `c6622a1` (today, post-Phase 1 Q1 — Genome 2.0 MVP + WAD-D instrumentation (client + backend) #67-merge)
• `25944850072` — `90df5772` (2026-05-15, the prior `chore: migrate xAI model references` commit)

Fix tracked in PR #68.