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>

apps/mobile/app/(app)/index.tsx

@@ -7,7 +7,7 @@ import { BlurView } from 'expo-blur';
 import { useAuthStore, usePacksStore, useSubscriptionStore } from '../../src/store';
 import { GradientBackground } from '../../src/components/ui';
 import { Paywall } from '../../src/components/paywall';
-import { CompactHeader, ContentRow, LiveDrawTile } from '../../src/components/discovery';
+import { CompactHeader, ContentRow, DaresTile, LiveDrawTile } from '../../src/components/discovery';
 import { colors, spacing, typography, radius } from '../../src/theme';
 import type { QuestionPack, Category } from '../../src/types';
 
@@ -117,6 +117,9 @@ export default function DiscoveryScreen() {
           {/* Live Draw Activity Tile */}
           <LiveDrawTile delay={100} />
 
+          {/* Dares */}
+          <DaresTile delay={150} />
+
           {/* Content Rows by Category */}
           {packsByCategory.map((group, index) => (
             <ContentRow