pub const EVENT_BLOCK_ACTIVITY: &str = "block:activity";Expand description
Fired by the agent-pane PTY read loop when an OSC 0/2 window-title sequence
from Claude Code is extracted. Carries the normalised conversation-topic string
so the frontend can surface it as a term:activity tab label.
Payload: { "blockId": "...", "activity": "auth refactor" }.