add Pulse conversational integration (Phase 3)
Expose window.openConversation() as a generic public API for any app to
pre-fill the chat bar and optionally auto-send. Add data-conversation
attributes and delegated click handler to Pulse elements — narrative,
calendar events, activities, todos, entities, and attention items — so
clicking any element pre-fills a context-appropriate prompt.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>