- Add forceReload option to ensureLoaded to avoid stat I/O in normal
paths while still detecting cross-service writes in the timer path
- Post isolated job summary back to main session (restores the old
isolation.postToMainPrefix behavior via delivery model)
- Update legacy migration tests to check delivery.channel instead of
payload.channel (normalization now moves delivery fields to top-level)
- Remove legacy deliver/channel/to/bestEffortDeliver from payload schema
- Update protocol conformance test for delivery modes
- Regenerate GatewayModels.swift (isolation -> delivery)
