提交关于N5功能，“involute_gear渐开线齿廓与齿条专用生成”的改动

backend/engine/cdsl_engine/runtime.py

@@ -12,7 +12,7 @@ from .build123d_adapter import Build123dGeometryAdapter
 from .capabilities import CapabilityAnalyzer, pattern_transform_blocker, sketch_ids_required_by_contract
 from .runtime_types import (
     AxisSpec, BendSpec, CapabilityResult, FeaturePlanNode, FeatureResult, HoleSpec, PlaneSpec,
-    ThreadSpec, Vector3,
+    GearSpec, RackSpec, ThreadSpec, Vector3,
     RuntimeDiagnostic, SelectorResolution, TopologyRecord, TopologyRegistry,
     vector_add, vector_cross, vector_dot, vector_scale, vector_subtract, vector_unit,
 )
@@ -29,6 +29,7 @@ ALL_ATOMIC_IDS = frozenset({
     "pattern_circular",
     "thread_add", "thread_cut",
     "bend_add",
+    "gear_add", "rack_add",
 })
 
 
@@ -92,6 +93,8 @@ class GeometryAdapter(Protocol):
     def sphere(self, radius_mm: float, center_mm: Vector3) -> Any: ...
     def thread_solid(self, spec: ThreadSpec) -> Any: ...
     def bend_solid(self, spec: BendSpec) -> Any: ...
+    def gear_solid(self, spec: GearSpec) -> Any: ...
+    def rack_solid(self, spec: RackSpec) -> Any: ...
     def hole_tool(self, spec: HoleSpec, starts: list[Vector3], inward: Vector3, through_depth_mm: float) -> Any: ...
     def body_center(self, body: Any) -> Vector3: ...
     def body_span(self, body: Any, direction: Vector3) -> float: ...
@@ -636,6 +639,51 @@ def _bend_executor(node: FeaturePlanNode, session: ExecutionSession, sketch: dic
     return _execute_bend(node, session)
 
 
+def _execute_gear(node: FeaturePlanNode, session: ExecutionSession) -> FeatureResult:
+    # 齿轮特征（gear_add）执行入口：按规格生成渐开线齿轮并入当前主体。
+    # 1. 解析并校验模数/齿数/齿宽/螺旋角与放置轴，非法输入抛出带具体原因的 ValueError。
+    spec = GearSpec.from_feature(node.params)
+    # 2. 由适配器门面生成沿 spec.axis 放置的齿轮实体（直齿/斜齿/人字齿）。
+    solid = session.adapter.gear_solid(spec)
+    # 3. 与当前主体做布尔并（fuse）后登记为新主体，并返回该特征的结果对象。
+    session.register_body(node.feature_id, session.adapter.fuse(session.body, solid), replay_node=node)
+    # 4. 小齿数根切风险：不阻断执行，附加 info 级诊断供完成报告如实披露。
+    diagnostics: list[RuntimeDiagnostic] = []
+    if spec.teeth_count < 17:
+        diagnostics.append(RuntimeDiagnostic(
+            code="undercut_risk",
+            message=(
+                f"Gear with {spec.teeth_count} teeth and a 20 degree pressure angle is undercut-prone; "
+                "standard involute geometry is generated without profile shift"
+            ),
+            feature_id=node.feature_id,
+        ))
+    return session.result(node, diagnostics=diagnostics)
+
+
+def _gear_executor(node: FeaturePlanNode, session: ExecutionSession, sketch: dict[str, Any] | None) -> FeatureResult:
+    # 齿轮特征（gear_add）不需要草图平面，丢弃该参数后执行。
+    del sketch
+    return _execute_gear(node, session)
+
+
+def _execute_rack(node: FeaturePlanNode, session: ExecutionSession) -> FeatureResult:
+    # 齿条特征（rack_add）执行入口：按规格生成直线齿条并入当前主体。
+    # 1. 解析并校验模数/齿数/厚度/压力角与放置轴，非法输入抛出带具体原因的 ValueError。
+    spec = RackSpec.from_feature(node.params)
+    # 2. 由适配器门面生成沿 spec.axis 放置的齿条实体（齿沿轴方向伸出）。
+    solid = session.adapter.rack_solid(spec)
+    # 3. 与当前主体做布尔并（fuse）后登记为新主体，并返回该特征的结果对象。
+    session.register_body(node.feature_id, session.adapter.fuse(session.body, solid), replay_node=node)
+    return session.result(node)
+
+
+def _rack_executor(node: FeaturePlanNode, session: ExecutionSession, sketch: dict[str, Any] | None) -> FeatureResult:
+    # 齿条特征（rack_add）不需要草图平面，丢弃该参数后执行。
+    del sketch
+    return _execute_rack(node, session)
+
+
 def _host_plane(resolution: SelectorResolution) -> PlaneSpec:
     if resolution.record is None:
         raise ValueError(resolution.diagnostic.message if resolution.diagnostic else "host face was not resolved")
@@ -1439,6 +1487,8 @@ EXECUTORS: dict[str, ExecutorFunction] = {
     "thread_add": _thread_executor,
     "thread_cut": _thread_executor,
     "bend_add": _bend_executor,
+    "gear_add": _gear_executor,
+    "rack_add": _rack_executor,
     "extrude_add_blind": _primary_executor,
     "extrude_add_two_sided": _primary_executor,
     "extrude_cut_blind": _primary_executor,