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/backend.rs

@@ -54,6 +54,12 @@ pub trait DocApiBackend {
     /// The text content of a Text/MText annotation. `Unsupported` for other kinds.
     fn text_content(&self, id: ObjectId) -> ApiResult<String>;
 
+    /// Add a `HATCH` (single closed polyline boundary); returns the fresh `ObjectId`.
+    fn add_hatch(&mut self, spec: &crate::ops::HatchSpec) -> ApiResult<ObjectId>;
+
+    /// A hatch's boundary loops (outer + islands) as closed polylines.
+    fn hatch_boundary(&self, id: ObjectId) -> ApiResult<Vec<Vec<[f64; 2]>>>;
+
     /// Can `id` be modified in place right now (exists, is the expected family,
     /// not on a locked layer)? Read-only pre-check used before mutations.
     /// Default: existence + not-locked (backends narrow the family check).

crates/ocs_doc_api/src/executor.rs

@@ -211,6 +211,16 @@ pub fn apply_op<B: DocApiBackend>(b: &mut B, op: Operation) -> ApiResult<Receipt
             b.finalize_op();
             OpOutcome::Updated(*id)
         }
+        Operation::CreateHatch(spec) => {
+            // Validate the boundary (>= 3 points) before committing.
+            if spec.boundary.len() < 3 {
+                return Err(ApiError::validation(name, "hatch boundary needs >= 3 points"));
+            }
+            b.push_undo(name);
+            let id = b.add_hatch(spec)?;
+            b.finalize_op();
+            OpOutcome::NewId(id)
+        }
     };
     Ok(Receipt {
         outcome: Some(outcome),
@@ -249,6 +259,7 @@ pub fn apply_queries<B: DocApiBackend>(b: &mut B, queries: Vec<Query>) -> ApiRes
             }
             Query::GetGeometryRevision => QueryResult::Revision(b.revision()),
             Query::GetTextContent { id } => QueryResult::TextContent(b.text_content(id)?),
+            Query::GetHatchBoundary { id } => QueryResult::HatchBoundary(b.hatch_boundary(id)?),
         };
         results.push(r);
     }

crates/ocs_doc_api/src/facade.rs

@@ -465,6 +465,16 @@ impl CurveCollection {
         let (s, id) = self.create_curve(Curve2Spec::XLine { origin, direction })?;
         Ok(XLine::new(s, id))
     }
+    /// A solid (or pattern) HATCH over a single closed polyline boundary.
+    pub fn create_hatch(&self, boundary: &[[f64; 2]], solid: bool) -> ApiResult<Entity> {
+        let receipt = self.session.apply_op(Operation::CreateHatch(crate::ops::HatchSpec {
+            boundary: boundary.to_vec(),
+            solid,
+        }))?;
+        let id = receipt.outcome.and_then(|o| o.new_id()).ok_or_else(|| ApiError::Transport("create_hatch returned no id".into()))?;
+        Ok(Entity::new(self.session.clone(), id))
+    }
+
     /// Single-line TEXT annotation.
     pub fn create_text(&self, value: &str, insertion_point: [f64; 3], height: f64, rotation: f64) -> ApiResult<Text> {
         let receipt = self.session.apply_op(Operation::CreateText(crate::ops::TextSpec {

crates/ocs_doc_api/src/gen/api_reference.md

@@ -113,6 +113,18 @@ Multi-line text annotation. content()/set_content() read+replace the value; tran
 - **content**(``) -> `String` — query `GetTextContent`
 - **set_content**(`value: &str`) -> `()` — op `SetTextContent`
 
+## `Entity` (acadrust `Hatch`, collection `curves`)
+
+Filled region over a closed polyline boundary. boundary() returns the loops; bounds from boundary; generic delete.
+
+### Constructors (`doc.curves()`)
+
+- **create_hatch**(`boundary: &[[f64; 2]], solid: bool`) -> `Entity`
+
+### Methods
+
+- **boundary**(``) -> `Vec<Vec<[f64; 2]>>` — query `GetHatchBoundary`
+
 ## `Entity` (acadrust `Insert`, collection `entities`)
 
 Block reference. Place an existing BlockRecord by name; transform moves its insert point.

crates/ocs_doc_api/src/gen/binding_schema.json

@@ -258,6 +258,25 @@
       ],
       "name": "MText"
     },
+    {
+      "acadrust_variant": "Hatch",
+      "collection": "curves",
+      "handle": "Entity",
+      "methods": [
+        {
+          "args": [],
+          "bulk": false,
+          "fixed": null,
+          "kind": "query",
+          "name": "boundary",
+          "op": null,
+          "query": "GetHatchBoundary",
+          "read_only": true,
+          "returns": "Vec<Vec<[f64; 2]>>"
+        }
+      ],
+      "name": "Hatch"
+    },
     {
       "acadrust_variant": "Insert",
       "collection": "entities",

crates/ocs_doc_api/src/gen/ops_gen.rs

@@ -7,7 +7,7 @@
 use serde::{Deserialize, Serialize};
 
 use crate::id::ObjectId;
-use crate::ops::{BoolOp, Curve2Spec, EntitySpec, InsertSpec, MTextSpec, PlacementSpec, SolidPrimitive, TextSpec, ViewportSpec};
+use crate::ops::{BoolOp, Curve2Spec, EntitySpec, HatchSpec, InsertSpec, MTextSpec, PlacementSpec, SolidPrimitive, TextSpec, ViewportSpec};
 
 /// A typed write operation (plan §5). Each variant is ONE atomic host call = one
 /// undo step. Append new variants at the END only.
@@ -36,4 +36,6 @@ pub enum Operation {
     CreateText(TextSpec),
     CreateMText(MTextSpec),
     SetTextContent { id: ObjectId, value: String },
+    // hatch
+    CreateHatch(HatchSpec),
 }

crates/ocs_doc_api/src/gen/query_gen.rs

@@ -21,4 +21,6 @@ pub enum Query {
     GetGeometryRevision,
     /// The text content of a Text/MText annotation.
     GetTextContent { id: ObjectId },
+    /// The boundary loops of a Hatch (outer + islands) as polylines.
+    GetHatchBoundary { id: ObjectId },
 }

crates/ocs_doc_api/src/ops.rs

@@ -96,6 +96,16 @@ pub struct MTextSpec {
     pub height: f64,
 }
 
+/// Construction spec for a `HATCH` with a single closed polyline boundary
+/// (straight segments). `solid` selects solid fill vs a pattern (pattern naming
+/// is a later refinement).
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct HatchSpec {
+    /// Closed boundary as an ordered polyline (first==last implied; closed).
+    pub boundary: Vec<[f64; 2]>,
+    pub solid: bool,
+}
+
 /// A rigid similarity (rotation + translation + optional uniform scale/reflection)
 /// as a plain-data mirror of `cadkernel::brep::transform`'s `Placement`
 /// (non-serde). Columns are the new basis axes; `origin` is the translation.
@@ -148,6 +158,7 @@ impl crate::gen::Operation {
             CreateText(_) => "CreateText",
             CreateMText(_) => "CreateMText",
             SetTextContent { .. } => "SetTextContent",
+            CreateHatch(_) => "CreateHatch",
         }
     }
 }

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",
         }
     }
 }