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/app/cad_agent/adapters/runtime.py

@@ -46,6 +46,9 @@ class ProfileCadRuntime:
             "selected_edges_exist": self._preflight_selected_edges_exist,
             "source_features_exist": self._preflight_source_features_exist,
             "mirror_plane_exists": self._preflight_mirror_plane_exists,
+            "loft_profiles_exist": self._preflight_loft_profiles_exist,
+            "loft_profiles_closed": self._preflight_loft_profiles_closed,
+            "loft_profiles_single_region": self._preflight_loft_profiles_single_region,
         }
         schema_path = Path(str(self.engine.__file__)).with_name("profile_schema.json")
         try:
@@ -990,6 +993,56 @@ class ProfileCadRuntime:
         if len(supplied) != 1 or not isinstance(selectors.get(supplied[0]), dict) or selectors[supplied[0]].get("kind") != "plane":
             raise RuntimeAdapterError("RUNTIME_PRECONDITION_FAILED: mirror plane is absent or stale")
 
+    def _loft_profile_sketches(self, fragment: dict[str, Any], base: dict[str, Any] | None) -> list[dict[str, Any]]:
+        """Resolve ``profile_sketch_ids`` against the base document's sketches."""
+        ids = [str(value) for value in fragment.get("feature", {}).get("params", {}).get("profile_sketch_ids") or ()]
+        sketches = (base or {}).get("geometry", {}).get("sketches") if isinstance((base or {}).get("geometry"), dict) else None
+        by_id = {
+            str(sketch.get("id") or ""): sketch
+            for sketch in (sketches or ())
+            if isinstance(sketch, dict)
+        }
+        resolved: list[dict[str, Any]] = []
+        for sketch_id in ids:
+            sketch = by_id.get(sketch_id)
+            if not isinstance(sketch, dict):
+                raise RuntimeAdapterError("RUNTIME_PRECONDITION_FAILED: loft profile sketch is not part of current head")
+            resolved.append(sketch)
+        if not resolved:
+            raise RuntimeAdapterError("RUNTIME_PRECONDITION_FAILED: loft has no profile sketches")
+        return resolved
+
+    def _preflight_loft_profiles_exist(self, fragment: dict[str, Any], _selectors: dict[str, dict[str, Any]], base: dict[str, Any] | None, _require_through: bool) -> None:
+        self._loft_profile_sketches(fragment, base)
+
+    def _preflight_loft_profiles_closed(self, fragment: dict[str, Any], _selectors: dict[str, dict[str, Any]], base: dict[str, Any] | None, _require_through: bool) -> None:
+        # circle/polygon 草图类型闭合性由 schema 保证；analytic_contours 需要
+        # 每条参与轮廓显式 closed。
+        for sketch in self._loft_profile_sketches(fragment, base):
+            profile = sketch.get("profile") if isinstance(sketch.get("profile"), dict) else None
+            if profile is None:
+                raise RuntimeAdapterError("RUNTIME_PRECONDITION_FAILED: loft profile sketch has no profile")
+            if profile.get("type") == "analytic_contours":
+                contours = profile.get("contours")
+                if not isinstance(contours, list) or not contours:
+                    raise RuntimeAdapterError("RUNTIME_PRECONDITION_FAILED: loft profile has no contours")
+                for contour in contours:
+                    if not isinstance(contour, dict) or not contour.get("closed"):
+                        raise RuntimeAdapterError("RUNTIME_PRECONDITION_FAILED: loft profile contour is not closed")
+
+    def _preflight_loft_profiles_single_region(self, fragment: dict[str, Any], _selectors: dict[str, dict[str, Any]], base: dict[str, Any] | None, _require_through: bool) -> None:
+        # 每个放样截面必须是单连通区域：analytic_contours 只允许恰好一条
+        # outer 闭合轮廓，不得携带 inner 环或 open 段。
+        for sketch in self._loft_profile_sketches(fragment, base):
+            profile = sketch.get("profile") if isinstance(sketch.get("profile"), dict) else None
+            if profile is None:
+                raise RuntimeAdapterError("RUNTIME_PRECONDITION_FAILED: loft profile sketch has no profile")
+            if profile.get("type") == "analytic_contours":
+                contours = [contour for contour in (profile.get("contours") or []) if isinstance(contour, dict)]
+                outer = [contour for contour in contours if contour.get("role") == "outer" and contour.get("closed")]
+                if len(outer) != 1 or len(outer) != len(contours):
+                    raise RuntimeAdapterError("RUNTIME_PRECONDITION_FAILED: loft profile must be a single closed region")
+
     @staticmethod
     def _polygon_self_intersects(vertices: list[Any]) -> bool:
         points = [(float(point[0]), float(point[1])) for point in vertices if isinstance(point, list) and len(point) == 2]