validate-cloud-sync

# Validate cloud sync Use the repository's two maintained references: - [CLOUD_SYNC_TESTING.md](../../../docs/CLOUD_SYNC_TESTING.md) for the deterministic harness, supported source sets, provider boundaries and `allTests`. - [CLOUD_SYNC_LIVE_TESTING.md](../../../docs/CLOUD_SYNC_LIVE_TESTING.md) for live provider setup, exact device1/device2 scenarios, the optional iPhone controller and evidence/report requirements. Resolve these paths from this skill's directory; run commands from the repository root. Choose the requested provider, supported platforms and test layer. A request for unit/regression coverage does not require live accounts or devices. For a new cloud provider, follow the onboarding section of the runbook and reuse the portable scenarios before adding provider-specific cases. Server accounts such as GReader and Feedbin use their own suites. For live checks, reuse the user's existing account/fixture authorization. If that scope is missing, establish it before mutations. Keep one actor per device and sequence writes according to the scenario; independent read-only checks can run in parallel. With delegation available, give bounded device work to cheaper agents and retain coordination and final verification in the parent. Keep the peer stale deliberately and capture the upload checkpoint before its local refresh. Distinguish upload completion from receiver delivery. Do not reissue an uncertain mutation; collect the controller result or inspect state. Record `PASS`, `FAIL`, `BLOCKED` or `NOT RUN` with evidence, then stop temporary controllers and link the local report. A controller's passing XCTest result is not a passing sync scenario. Do not publish artifacts as part of validation.