Build-verified attempt to port the Java EuclideanCyclicConvergenceTest
(cathead, "circular hole edge" φ = π−0.1).
- ✅ GREEN `CyclicCircularEdge_PhiEntersGradient_CatHead`: solver-free
cross-validation that the circular-edge φ target enters the cyclic edge
gradient exactly (ΔG_e = −Δφ_e at 1e-12; no other component moves).
- ⏸️ DISABLED `CyclicCircularEdge_CatHead_JavaXVal`: the full Java convergence
assertion (α_opp+α_opp = π−0.1), kept with golden semantics. Auto-activates
once the edge-DOF Hessian lands.
Build-verification finding: `newton_euclidean` -> `euclidean_hessian` throws
"edge DOFs are not supported" — the cyclic full solve is blocked by a missing
edge-DOF Euclidean Hessian (gradient supports edge DOFs, analytic Hessian does
not). Spherical convergence (Tier-1 #2) is already covered by test_newton_solver.
Documented in doc/reviewer/java-ignore-crossvalidation.md.
All 13 EuclideanFunctional tests pass (1 disabled).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>