docs: record 2026-05-28 full-library scan findings in roadmap

Cross-referenced all 232 Java classes against the roadmap. New plan
entries for genuinely-useful, previously-unplanned items:
- 9g.1 conformal quality measures (Isothermicity, ConformalEquivalence,
  FlippedTriangles, LengthCrossRatio + ConvergenceUtility metrics)
- 9g.2 optional period-matrix convergence experiment (method only;
  Java harness depends on Mathematica/JLink + jReality, not ported)
- DEC operator layer (heds/dec/) noted as a 10a prerequisite
- HomotopyUtility -> 10a (explicit generator cycles; not covered by
  cut_graph.hpp, which yields only the 2g cut edges)
- SurfaceCurveUtility -> 9c; MercatorTextureProjection -> 9d.3 companion

Documented as deliberately out-of-scope: SpanningTreeUtility (subsumed
by cut_graph.hpp), convergence/* harness, datasource/* (jReality viewer
decoration), *Big arbitrary-precision geometry, jReality GUI, and the
MTJ/Tao/PETSc solver bindings.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

doc/roadmap/java-parity.md

@@ -58,6 +58,7 @@ They are candidates for Phase 9 or Phase 10.
 | `DiscreteHarmonicFormUtility` (657 lines) | Discrete harmonic 1-forms via cotangent Laplacian (Hodge theory) | 10a prerequisite |
 | `DiscreteHolomorphicFormUtility` (285 lines) | Holomorphic differentials via Mercat complex structure | 10a (Bobenko-Springborn 2004 §6) |
 | `CanonicalBasisUtility` (337 lines) | Symplectic homology basis with intersection-form normalisation | 10a prerequisite |
+| `HomotopyUtility` (57 lines) | Reconstructs explicit generator cycles (bridge + tree path) — NOT covered by `cut_graph.hpp` (which gives only the 2g cut edges). Verified 2026-05-28. | 10a |
 | `DiscreteRiemannUtility` (186 lines) | Period matrix τ, Siegel reduction (genus g) | 10b |
 | `DualityUtility` (308 lines), `HomologyUtility` (122 lines) | Primal/dual cohomology, cycle generators | 10a support |
 | `HyperbolicCyclicFunctional` (530 lines) | Discrete hyperbolic conformal energy (analogue of Euclidean) — completes the geometry suite | 10b–c |
@@ -66,10 +67,30 @@ They are candidates for Phase 9 or Phase 10.
 | `StereographicUnwrapper` (266 lines) | Stereographic projection S²→ℂ + Möbius centring — converts the Spherical-DCE output into a 2-D atlas | 10b' (Sphere visualisation) |
 | `CircleDomainUnwrapper` (570 lines) | Conformal map of a multiply-connected planar region onto a disk-with-holes — classical complex-analysis use case | 11+ (new use-case class) |
 | `ElectrostaticSphereFunctional`, `MobiusCenteringFunctional` | Sphere-domain pre-processing functionals | 10c (optional) |
+| `IsothermicityMeasure` (113), `DiscreteConformalEquivalencemMeasure` (82), `FlippedTriangles` (17), `LengthCrossRatio` (12) | Quantitative conformal-quality / embedding-validity measures (math is GUI-independent) | **9g** (added 2026-05-28) |
+| `DEC`, `AbstractDECOperator`, `DECPairing`, `DualChain`, `DualForm` (`heds/dec/`) | Discrete-exterior-calculus operator layer (d / ⋆ / pairing) — foundation the Phase-10a form utilities sit on | **10a prerequisite** (added 2026-05-28) |
+| `SurfaceCurveUtility` (360) | Curve operations on the surface (cut-path tracing) — supports 9c polygon construction | **9c** (added 2026-05-28) |
 
 Note: items marked as *new research* (e.g. Inversive Distance, HyperIdeal Hessian variants)
 are tracked separately in `doc/roadmap/research-track.md`.
 
+### 2026-05-28 scan — valuable items that had been in *no* phase
+
+A class-by-class cross-reference of all 232 Java production classes against the
+roadmap found that the "big math" (Schottky 11a, Koebe 10c′/10f, quasi-isothermic
+10e, circle-pattern layout 9e) is all already planned.  Three genuinely useful
+items were unrecorded and have now been added above:
+1. **Conformal-quality measures** → new **Phase 9g** (small, no dependencies; raises
+   validation coverage for the already-shipped pipeline).
+2. **DEC operator layer** (`heds/dec/`) → noted as a **Phase 10a prerequisite** (the
+   form utilities assume these primitives exist).
+3. **`SurfaceCurveUtility`** → folded into the **Phase 9c** source list.
+
+Everything else unmentioned is intentionally out of scope: the `plugin/*` jReality
+Swing GUI, the `MTJ*`/`Tao*`/`*PETSc` solver bindings (replaced by Eigen), the
+convergence/`*Series` test harness, and the `*Big` arbitrary-precision geometry
+(`P2Big`/`PnBig`/`RnBig` — deliberately dropped in favour of `Simple_cartesian<double>`).
+
 ---
 
 ## Java packages not yet in the roadmap — 2026 full-library scan
@@ -154,6 +175,9 @@ Entirely absent from the current roadmap.
 | `EuclideanUnwrapperPETSc` / `SphericalNormalizerPETSc` | PETSc solver binding — replaced by Eigen |
 | `Search` | CoHDS-specific graph search — replaced by CGAL halfedge iteration |
 | `SparseUtility` | Colt sparse matrix utils — replaced by Eigen |
+| `SpanningTreeUtility` | Primal + dual spanning tree — already implemented inline in `cut_graph.hpp` (tree-cotree Steps 1+2). Verified 2026-05-28. |
+| `convergence/*` harness (CLI driver, ~1400 lines) | The driver depends on Mathematica (JLink) + jReality OBJ reader + LoopLinear. Do not port the harness — only its math: quality measures → 9g.1, study method → 9g.2 (optional). Verified 2026-05-28. |
+| `datasource/*` (`ConicalEdgesDataSource`, `CylinderEdgesDataSource`) | jReality SceneGraph viewer decoration (draws cone/cylinder edge arcs) — NOT example geometry; nothing to harvest. Verified 2026-05-28. |
 
 ---