feat: improve Chronicle ConversationBlock readability and add project status doc

- ConversationBlock: chat bubble layout, whitespace-pre-wrap, *italic* rendering
- ConversationBlock: increase border opacity, message spacing, default visible count
- ChronicleView: remove unnecessary AnimatePresence wrapper
- InterventionBar: fix whisper API body field names
- simulation store: add loadChronicleFromDB for persistent chronicle loading
- docs: add comprehensive PROJECT_STATUS.md with architecture, progress, and design

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sonwr