New table stores:
- Edge identification (from_node → to_node)
- Analysis results (confidence, level, method)
- Proposed mapping (AI-generated)
- User mapping (overrides)
- Confirmation status
Indexes:
- By flow_id for listing
- Unique on (flow_id, from_node, to_node) for upsert
This supports the edge analysis API for visual wiring in the canvas.
Co-authored-by: Dan
