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/src/query.rs

@@ -45,6 +45,8 @@ pub enum QueryResult {
     Revision(GeometryRevision),
     /// The text content of a Text/MText annotation.
     TextContent(String),
+    /// A hatch's boundary loops (outer + islands), each a closed polyline.
+    HatchBoundary(Vec<Vec<[f64; 2]>>),
 }
 
 /// Convenience: the query name for diagnostics.
@@ -59,6 +61,7 @@ impl crate::gen::Query {
             GetIntersects { .. } => "GetIntersects",
             GetGeometryRevision => "GetGeometryRevision",
             GetTextContent { .. } => "GetTextContent",
+            GetHatchBoundary { .. } => "GetHatchBoundary",
         }
     }
 }