feat(api): migrate widget intakes to unified form-submissions #195

Blocked by sydevs/SahajCloud#695. Do not start integration until that issue's Phase 3 PR is merged to main. Cleared 2026-09-16. Phase 3 merged as sydevs/SahajCloud#801 and is deployed, so pnpm types:cms now pulls the user-submissions shape.

The joint release did not happen: Phase 3 shipped alone, ahead of this repo and of sydevs/WeMeditateWeb's sibling child. main still posts to the deleted endpoints (src/config/api/mutate.ts:138 and :288), so event registration and report-an-issue fail against the live CMS today. This is a repair, not a migration to schedule. The cutover is still hard: no shims.

Summary

The CMS is unifying every public intake on one user-submissions collection (sydevs/SahajCloud#695). Three widget call sites move to it (voting needs no widget change -- see below); the request/response envelopes are Payload's built-in ones, which #171 already prepared this client for (errors[].data.code).

Proposed changes

Migrate each call site to POST /api/user-submissions (Turnstile stays in the x-turnstile-token header, as already sent):

1. Event registration (today POST /api/events/{id}/register): body becomes { type: 'registration', event, startingAt, senderEmail, submissionData: [name, locale, question answers…], subscribe? }. Still synchronous — eligibility refusals arrive as coded 404/409 at errors[].data.code (not the old top-level code), and the success doc carries uuid (replaces registration.uuid in the old shape). The opt-in flag spawns the subscribe row server-side — no second call.
2. Report an issue (today POST /api/user-messages, feat(report): migrate the issue-report form to POST /api/user-messages #187): becomes { type: 'contact', senderEmail, submissionData: [subject, message, context…] }. No form reference — recipient falls back to the CMS contact address, as today.
3. Event proposals (today POST /api/event-submissions): becomes { type: 'proposal', event?, proposed, senderEmail, submissionData: [submitter name/note] }.
4. Confirm/deny votes -- no widget change. Voting stays on the CMS-hosted feedback page (email link -- signed-token page -- vote -- redirect back to the atlas); the widget keeps only its existing read of the redirect param (usePostEventFeedback). The client-facing registrations update path is deleted CMS-side -- nothing here calls it, and nothing should start to.

Then pnpm types:cms against SahajCloud main: Registration / UserMessage / EventSubmission types disappear, UserSubmission gains the typed columns — fix what the compiler flags (RegistrationForm, ReportIssueForm, submission + feedback flows, store.ts types).

Acceptance criteria

• Registering from the widget returns the uuid synchronously; a full/ended event shows the correct refusal (code read from errors[].data.code).
• Registering with the mailing-list opt-in produces the linked subscribe row CMS-side with no extra widget call.
• Report-an-issue and event proposals land as contact / proposal rows and screen/deliver as before.
• The post-event feedback flow still works end-to-end (email link -- CMS feedback page -- atlas redirect renders the post-vote card) with no widget code change.
• No code references the removed endpoints or types; pnpm lint && pnpm typecheck && pnpm test:run pass.

References

• Tracker: feat(api)!: unify public intakes on the form-submissions pipeline SahajCloud#695 (design + wire contract)
• feat(report): migrate the issue-report form to POST /api/user-messages #171 (error-envelope positions), feat(report): migrate the issue-report form to POST /api/user-messages #187 (report-issue on user-messages — the call being re-pointed), feat(turnstile): treat Turnstile as essential — gate registration, and stop degrading to mailto #184 (Turnstile handling)