feat: add adapter tool discovery

[chaizhenhua]

Summary

• add adapter tool catalog schema/probe support and carry effective catalogs through worker capabilities
• expose adapter tool catalogs through server APIs and wire the AgentEditor picker to adapter-backed catalogs
• capture ACP AvailableCommandsUpdate during session setup and prompt streams, including regression coverage and real-CLI probe example coverage

Validation

• cargo check -p oversight-worker --examples
• cargo test -p oversight-worker tools_observer -- --nocapture
• cargo test -p oversight-worker dynamic_discovery_flows_acp_event_to_capabilities -- --nocapture
• pre-push lefthook validate passed during branch push