fix(messages): stamp agent messages with workflow.now() for monotonic ordering #1525

Job	Run time
find-tutorials	6s
test-00_sync/030_langgraph	3m 40s
test-10_async/00_base/020_streaming	2m 2s
test-00_sync/000_hello_acp	1m 58s
test-10_async/00_base/100_langgraph	2m 5s
test-00_sync/020_streaming	2m 16s
test-00_sync/010_multiturn	2m 28s
test-10_async/00_base/030_tracing	1m 56s
test-10_async/00_base/000_hello_acp	1m 58s
test-10_async/10_temporal/000_hello_acp	1m 59s
test-10_async/00_base/010_multiturn	2m 11s
test-10_async/10_temporal/010_agent_chat	4m 29s
test-10_async/10_temporal/020_state_machine	2m 14s
test-10_async/00_base/080_batch_events	3m 8s
test-10_async/10_temporal/060_open_ai_agents_sdk_hello_world	1m 55s
test-10_async/10_temporal/050_agent_chat_guardrails	1m 54s
test-10_async/10_temporal/030_custom_activities	1m 52s
test-10_async/00_base/040_other_sdks	3m 39s
test-10_async/10_temporal/070_open_ai_agents_sdk_tools	1m 56s
test-10_async/10_temporal/080_open_ai_agents_sdk_human_in_the_loop	2m 5s
test-10_async/10_temporal/090_claude_agents_sdk_mvp	2m 6s
Test Summary	4s
	48m 1s

Provide feedback