feat(release): enforce manifest and Info.plist release invariants

Extend release-preflight to reject an Android manifest missing the
READ_MEDIA_IMAGES/READ_MEDIA_VIDEO tools:node="remove" attributes and
an iOS Info.plist that regained dev-launcher-only keys, both
regressions introduced silently by expo prebuild during the SDK 54 to
56 upgrade.

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

apps/mobile/AGENTS.md

@@ -13,3 +13,5 @@ native iOS/Android targets.
 - Add stable accessibility labels or `testID` values for critical interactions.
 - Verify focused Jest tests, typecheck, lint, then native/Expo behavior as risk
   requires. UI work needs observable simulator evidence.
+- Before and after any `expo prebuild`, follow the "After native regeneration"
+  checklist in `docs/releasing.md`.