feat(dares): ship the dares loop to mobile

Completes the half-built dares feature: send a dare, respond, report done,
confirm, and get a push notification on every transition.

Backend (apps/api):
- New `dares` domain with couple-shared premium entitlement, a free weekly
  send allowance, and server-enforced actor/state rules on every transition.
- `submitted` status so the recipient reports completion and the sender
  confirms, rather than the sender guessing.
- Notifications ride the existing operations outbox via a trigger on
  `sent_dares`. Push copy is generic; store compliance forbids dare text in a
  preview and a test asserts no payload leaks it.
- Worker expiry sweep now covers `pending` as well as `active`/`submitted`;
  an invitation nobody opened previously stayed open forever.

Fixes two latent defects:
- Deleting any dare that had been sent aborted with a check violation, because
  `dare_id` is ON DELETE SET NULL while `sent_dares_dare_or_custom_check`
  required it. Dare text is now snapshotted at send time, which also keeps a
  couple's history stable across catalogue edits.
- The free send allowance was raceable: concurrent requests all read the same
  count and every one succeeded. The count and insert are now serialized on
  the sender's profile row.

Also ports `content_status` review metadata to the API catalogue, which had no
store-safety gating at all, and mirrors the review decision already enforced on
the legacy catalogue.

Mobile: dares screen (active/send/history), send sheet with duration presets,
home tile badging incoming dares, paywall on both proactive and 402 paths.

Verified: lint, typecheck, 379 unit tests, build, 71 integration tests against
local PostgreSQL.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/index.md

@@ -20,6 +20,7 @@ historical notes. Agents should load only the section relevant to their task.
 - [Subscriptions](subscription-system.md)
 - [Redemption codes](product/redemption.md)
 - [Mobile release process](releasing.md)
+- [Dares loop](dares-loop.md)
 
 ## Feature and implementation references
 
@@ -29,7 +30,7 @@ partially implemented states. Confirm claims against current code.
 - `admin-question-types-plan.md`
 - [Universal catalogue safety plan](product/catalog-content-safety-plan.md)
 - `content-balance-implementation.md`
-- `dares-feature.md`
+- `dares-feature.md` (superseded by [Dares loop](dares-loop.md))
 - `live-draw-feature-plan.md`
 - `NEW_QUESTION_TYPES.md`
 - `oversized-file-inventory.md`