Establishes mandatory standards for Mermaid diagrams in Blue documents:
- Neutral theme required for dark/light mode compatibility
- Leaf node counting for LR flow warnings (>3 nodes)
- Plain text for architecture labels (no emoji color injection)
- Shape semantics advisory for new diagrams
- Auto-fix for theme declaration only (colors require manual review)
Includes alignment dialogue with 10/10 tensions resolved across 3 rounds.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
