fix(packaging): guard agentex-client surface, bump floor, smoke-test wheel install #1696

Job	Run time
find-tutorials	4s
test-00_sync/020_streaming	3m 8s
test-00_sync/050_openai_agents_local_sandbox	2m 40s
test-00_sync/040_pydantic_ai	2m 42s
test-00_sync/010_multiturn	3m 9s
test-00_sync/000_hello_acp	2m 35s
test-10_async/00_base/030_tracing	2m 36s
test-10_async/00_base/010_multiturn	6m 37s
test-00_sync/030_langgraph	3m 35s
test-10_async/00_base/080_batch_events	3m 42s
test-10_async/00_base/040_other_sdks	4m 11s
test-10_async/00_base/100_langgraph	2m 52s
test-10_async/00_base/020_streaming	2m 55s
test-10_async/00_base/110_pydantic_ai	2m 41s
test-10_async/00_base/000_hello_acp	2m 56s
test-10_async/10_temporal/000_hello_acp	2m 35s
test-10_async/00_base/120_openai_agents_local_sandbox	4m 50s
test-10_async/10_temporal/020_state_machine	3m 52s
test-10_async/10_temporal/010_agent_chat	3m 21s
test-10_async/10_temporal/090_claude_agents_sdk_mvp	7m 40s
test-10_async/10_temporal/060_open_ai_agents_sdk_hello_world	2m 44s
test-10_async/10_temporal/080_open_ai_agents_sdk_human_in_the_loop	2m 44s
test-10_async/10_temporal/130_langgraph	2m 45s
test-10_async/10_temporal/050_agent_chat_guardrails	2m 49s
test-10_async/10_temporal/030_custom_activities	2m 19s
test-10_async/10_temporal/070_open_ai_agents_sdk_tools	2m 40s
test-10_async/10_temporal/120_openai_agents_local_sandbox	2m 47s
test-10_async/10_temporal/110_pydantic_ai	2m 36s
Test Summary	5s
	1h 30m 10s

Provide feedback