docs: add StereographicUnwrapper + CircleDomainUnwrapper to roadmap

Audit found that 2 of the 4 Java-port candidates from the conformal-
mapping discussion were missing from the documentation:

* StereographicUnwrapper (266 Java LoC) — projects spherical layout
  S² → ℂ via stereographic projection + Möbius centring.  Closes the
  visualisation gap from discrete_conformal_map_spherical() which
  currently returns Point_3 on S²; downstream uses typically want a
  2-D atlas.  Suggested phase: 10b' (alternative methods, parallel
  to Hyperbolic / Quasi-isothermic).  Effort: small (~3 days).

* CircleDomainUnwrapper (570 Java LoC) — conformal map of a
  multiply-connected planar region onto a disk-with-holes (Koebe's
  general uniformization theorem 1909).  A use-case class
  conformallab++ does not currently cover (annulus, slit torus,
  fluid flow around obstacles, electrostatics with multiple
  conductors).  Suggested phase: 11c.  Effort: large (~2 weeks).

Added to all three roadmap documents:

* doc/roadmap/java-parity.md      — worth-porting table extended
* doc/roadmap/research-track.md   — Java-backlog summary extended
* doc/roadmap/phases.md           — Phase 10b' bullet + new
                                    Phase 11c block with full math
                                    context (Koebe 1909 reference,
                                    classical complex-analysis use cases).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

doc/roadmap/java-parity.md

@@ -61,6 +61,8 @@ They are candidates for Phase 9 or Phase 10.
 | `HyperbolicCyclicFunctional` (530 lines) | Discrete hyperbolic conformal energy (analogue of Euclidean) — completes the geometry suite | 10b–c |
 | `QuasiisothermicUtility` + `SinConditionApplication` (~1200 lines) | Lawson-correspondence parametrisation, sin-condition functional | 10b |
 | `KoebePolyhedron` (321 lines) | Koebe–Andreev–Thurston circle-packing construction | 10c |
+| `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) |
 
 Note: items marked as *new research* (e.g. Inversive Distance, HyperIdeal Hessian variants)

doc/roadmap/phases.md

@@ -223,6 +223,12 @@ Phase 10   Global uniformization for genus g ≥ 2
          QuasiisothermicUtility.java + SinConditionApplication.java
          (~1 200 Java lines combined).
        → MobiusCenteringFunctional (Java, 289 lines) — sphere centering.
+       → StereographicUnwrapper (Java, 266 lines) — projects the
+         spherical layout S²→ℂ via stereographic projection plus a
+         Möbius centring step.  Closes the visualisation gap from
+         `discrete_conformal_map_spherical()` (currently outputs
+         Point_3 on S²; many downstream uses want a 2-D atlas).
+         Effort: small (~3 days).
        Each independent; can be tackled in any order.
 
 10c  Full uniformization for genus g ≥ 2
@@ -292,7 +298,24 @@ Phase 10   Global uniformization for genus g ≥ 2
                             visualisation; consider porting only the
                             algorithmic core.
 
-Both items are tracked here so the project memory is preserved; they
+11c   Multiply-connected planar conformal maps  (CircleDomainUnwrapper)
-are NOT roadmap commitments.  See `research-track.md` for the formal
+        Java source:        unwrapper/CircleDomainUnwrapper.java (570 LoC)
-research-versus-port classification before starting either.
+        Mathematical basis: Riemann mapping theorem for multiply-
+                            connected domains — every n-connected planar
+                            region is conformally equivalent to a disk
+                            with (n−1) round holes (Koebe's "general
+                            uniformization theorem", 1909).
+        Use case:           Classical complex-analysis problems —
+                            conformal mapping of an annulus, a torus
+                            slit on a plane, fluid flow around obstacles,
+                            electrostatics with multiple conductors.
+                            **A use-case class conformallab++ does not
+                            currently cover.**
+        Requires:           Phase 10b' QuasiisothermicUtility or the
+                            CP-Euclidean machinery from Phase 9a.1.
+        Effort:             large (~2 weeks).
+
+All three items are tracked here so the project memory is preserved;
+none of them are roadmap commitments.  See `research-track.md` for the
+formal research-versus-port classification before starting any.
 ```

doc/roadmap/research-track.md

@@ -294,6 +294,8 @@ These are tracked separately in
 | `HyperbolicCyclicFunctional` | 530 | 10b–c | 2 weeks |
 | `QuasiisothermicUtility` + `SinConditionApplication` | ~1 200 | 10b | 3 weeks |
 | `KoebePolyhedron` | 321 | 10c | 2 weeks |
+| `StereographicUnwrapper` | 266 | 10b' (Sphere→ℂ atlas) | small (~3 days) |
+| `CircleDomainUnwrapper` | 570 | 11+ (multiply-connected planar regions) | large (~2 weeks) |
 | `MobiusCenteringFunctional`, `ElectrostaticSphereFunctional` | 289 + 127 | 10c (optional) | small |
 
 Total identified backlog: ~6 500 Java lines, estimated ~5 months of work