ocs_doc_api: Phase 4 set_view + viewport-view query

- SetViewportView op + GetViewportView query (append-only).
- backend set_viewport_view (update Viewport.view_target/view_height) + viewport_view.
- facade Entity::set_view/viewport_view (Viewport returns Entity).
- spec Viewport methods; api_reference + binding_schema regenerated; mocks + baseline.
- Test phase4_set_view_and_view_query -> 609 host lib + 3 consistency green.
- Phase 4 complete.

crates/ocs_doc_api/tests/spec_wire_consistency.rs

@@ -59,6 +59,7 @@ fn operation_variants() -> Vec<String> {
         Operation::CreateHatch(ocs_doc_api::ops::HatchSpec { boundary: vec![], solid: true }),
         Operation::CreateDimensionLinear(ocs_doc_api::ops::DimensionSpec { first_point: [0.0; 3], second_point: [0.0; 3], definition_point: [0.0; 3] }),
         Operation::SetAttribute { id: ObjectId::from_u64(0), tag: String::new(), value: String::new() },
+        Operation::SetViewportView { id: ObjectId::from_u64(0), view_target: [0.0; 3], view_height: 0.0 },
     ];
     // Derive the variant names by serializing a probe of each and reading the
     // bincode variant index -> name map is not available; instead match by
@@ -88,6 +89,7 @@ fn query_variants() -> Vec<String> {
         Query::GetDimensionMeasurement { id: ObjectId::from_u64(0) },
         Query::GetAttributes { id: ObjectId::from_u64(0) },
         Query::GetBlockEntities { block_name: String::new() },
+        Query::GetViewportView { id: ObjectId::from_u64(0) },
     ];
     marker
         .iter()
@@ -144,6 +146,7 @@ const OPERATION_BASELINE: &[&str] = &[
     "CreateHatch",
     "CreateDimensionLinear",
     "SetAttribute",
+    "SetViewportView",
 ];
 
 /// Recorded baseline of the `Query` variant order.
@@ -159,6 +162,7 @@ const QUERY_BASELINE: &[&str] = &[
     "GetDimensionMeasurement",
     "GetAttributes",
     "GetBlockEntities",
+    "GetViewportView",
 ];
 
 #[test]