ocs_doc_api: Phase 2b-b (Hatch)

- CreateHatch(HatchSpec) op + GetHatchBoundary query (append-only).
- HatchSpec{boundary: Vec<[f64;2]>, solid}; executor validates >= 3 boundary points.
- backend add_hatch (Line-edge BoundaryPath, solid/pattern) + hatch_boundary
  (reconstruct loops from Line edges; non-line edges -> Unsupported).
- Hatch bounds from boundary edges; facade create_hatch + Entity handle.
- spec Hatch family; api_reference + binding_schema regenerated; mocks + baseline.
- Test phase2b_hatch_create_boundary_bounds_delete -> 606 host lib + 8 crate + 3 consistency green.

crates/ocs_doc_api/spec/entities.toml

@@ -290,6 +290,27 @@ op = "SetTextContent"
 args = [{ name = "value", ty = "&str" }]
 returns = "()"
 
+# ============================================================================
+# HATCH FAMILY (phase 2b) — filled regions
+# ============================================================================
+[[family]]
+name = "Hatch"
+acadrust_variant = "Hatch"
+handle = "Entity"
+collection = "curves"
+description = "Filled region over a closed polyline boundary. boundary() returns the loops; bounds from boundary; generic delete."
+
+[[family.constructor]]
+name = "create_hatch"
+args = [{ name = "boundary", ty = "&[[f64; 2]]" }, { name = "solid", ty = "bool" }]
+op = "CreateHatch"
+
+[[family.method]]
+name = "boundary"
+kind = "query"
+query = "GetHatchBoundary"
+returns = "Vec<Vec<[f64; 2]>>"
+
 # ============================================================================
 # CONTAINER FAMILY (phase 3) — block references
 # ============================================================================