Function build_test_chain_executor 

pub fn build_test_chain_executor() -> ChainExecutor

Build the upstream-test chain executor from the production connector registry (eggress-server::build_chain_executor), not a CLI-local reimplementation.

Diagnostic coverage therefore tracks live connection support: adding a production-supported upstream protocol never requires a separate registration in CLI test code. Both eggress upstream test --mode proxy and pproxy --test execute through this path.