- Hoist resolveFallbackChainForCallOmoAgent before sync/background branch
so sync executor also receives the fallback chain
- Add fallbackChain parameter to sync-executor with setSessionFallbackChain
- Mock connected-providers-cache in event.model-fallback tests for
deterministic behavior (no dependency on local cache files)
- Update test expectations to account for no-op fallback skip when
normalized current model matches first fallback entry
- Add cache spy isolation for subagent-resolver fallback_models tests
YeonGyu-Kim