[codex] Route opencode chat models through Zen #6542

Job	Run time
build-and-check	2m 52s
test-integration-packages/internal	1m 9s
test-integration-packages/billing	1m 3s
test-integration-web	42s
test-integration-packages/agent-runtime	49s
test-integration-common	55s
test-integration-sdk	1m 13s
test-integration-cli	44s
test-packages/agent-runtime	44s
test-common	47s
test-.agents	40s
test-packages/internal	46s
test-packages/billing	50s
test-cli	1m 1s
test-sdk	52s
test-web	1m 35s
	16m 42s

Provide feedback