Verify connector target alignment

[theclaymethod]

Summary

• resolve line, path, polyline, and polygon endpoints in viewport coordinates
• pair connectors to declared target nodes and validate side-center anchors
• document target/anchor tagging in the diagram protocol

Verification

• 33 Artifacture tests pass
• verifier JSON catalogs parse
• upgraded arrow check passes against the corrected cost-structure and review-portfolio slides
• the same check caught their prior vertical drift and undersized air gaps