Engine to Product: Three Interfaces, One Codebase

You built the engine. Four layers of deterministic comparison, 1,875 tests, confidence scoring, alignment ladder. Great. Nobody can use it. A library isn't a product. The comparison engine in cad-dxf-agent could compare two DXF files with sub-thousandth precision — but only if you imported it in a Python script, instantiated the right classes, and knew the method signatures. That's fine for me. It's useless for the machinist reviewing revision changes. This week was about wiring three interfaces onto one engine: a CLI for power users, a REST API for integrations, and a frontend wizard for everyone else. Four PRs, 76 new tests. The Problem That Forced Manual Alignment The automatic alignment ladder (identity → anchor → feature) handles most drawings. But some files have huge coordinate offsets — one sheet drafted at origin, the revision drafted 10,000 inches away — and no shared anchor blocks to triangulate from. The ladder tries all three strategies and fails gracefully. But "we can't