epiphany/crates/epiphany-engrave/README.md

epiphany-engrave

Agent I's engraving constraint solver (spec Chapter 9): turns a ConstrainedLayoutIR into a ResolvedLayoutIR with real geometry. It is the production-side replacement for epiphany-layout-ir's interface-only StubSolver; the two live in separate crates so the spec's core/product boundary stays sharp.

Status: honest scaffold (renderer-against-stub phase)

Per the QUICKSTART development pattern, Agent I builds the SVG renderer (epiphany-render-svg) against the stub solver first, then grows this crate into the real two-pass spring solver. This commit is the first increment:

• Engraver runs a deterministic horizontal spacing pass (the first axis of the planned two-pass spring layout): each spring slot is placed left-to-right by its preferred width instead of being echoed verbatim.
• It honestly reports SolverTier::Stub — it does not yet evaluate the IR's declared hard constraints or compute quality metrics, so it has not earned Minimal. It is promoted to Minimal in the change that lands real constraint satisfaction.

The vertical spring pass, soft-constraint solve, hard-constraint evaluation, and the quality-metric vector are the next-phase / Phase-3 work. See DECISIONS.md.

use epiphany_engrave::Engraver;
use epiphany_layout_ir::{ConstraintSolver, SolverConfig};

let report = Engraver.solve(&constrained_ir, &SolverConfig::default());
assert!(report.satisfied_hard_constraints); // for constraint-free stub-pipeline input
let resolved = report.layout;               // hand to epiphany-render-svg