4d641a52b4
Wire EventBus through task runtime so subagent lifecycle and progress events propagate to the TUI. Add SessionObserverRegistry to track active sessions, and a session observer overlay accessible via Ctrl+S that shows a picker of running subagents and a read-only transcript viewer that reads the subagent's session JSONL file to display thinking, text, tool calls, and results. - Add TASK_SUBAGENT_LIFECYCLE_CHANNEL for start/end events - Add SubagentProgressPayload.sessionFile for session file tracking - Pass eventBus through sdk.ts -> main.ts -> InteractiveMode - SessionObserverRegistry with multi-listener onChange pattern - Overlay picker preserves selection position across live refreshes - Viewer renders full transcript from session JSONL (thinking, text, tool calls with smart arg summaries, inline tool results)