- Rewrite DebugMermaidDiagram edge matching to use BFS graph traversal
- Build graph from SVG edges (L_FROM_TO_INDEX format) for path finding
- Handle phase boundary disconnections with bidirectional BFS:
- Forward BFS finds all nodes reachable from start
- Backward BFS finds all nodes that can reach end
- Combines both to highlight intermediate nodes across phase gaps
- Remove complex pattern matching in favor of graph-based approach
- Auto-compute edge IDs as {nodeId}_{optionValue} in loader.ts
- Add computeEdgeId() helper to schema.ts for consistent edge ID generation
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>