feat: add headless runner entry points

New file: runner.py with three entry points for silorunner:
- dag_extract(input_path, output_path): extract feature DAG as JSON
- validate(input_path, output_path): rebuild features, report pass/fail
- export(input_path, output_path, format): export to STEP/IGES/STL/OBJ

Invoked via: create --console -e 'from runner import dag_extract; ...'

Closes kindred/create#217

freecad/runner.py

@@ -0,0 +1,156 @@
+"""Headless runner entry points for silorunner compute jobs.
+
+These functions are invoked via ``create --console -e`` by the
+silorunner binary.  They must work without a display server.
+
+Entry Points
+------------
+dag_extract(input_path, output_path)
+    Extract feature DAG and write JSON.
+validate(input_path, output_path)
+    Rebuild all features and report pass/fail per node.
+export(input_path, output_path, format='step')
+    Export geometry to STEP, IGES, STL, or OBJ.
+"""
+
+import json
+
+import FreeCAD
+
+
+def dag_extract(input_path, output_path):
+    """Extract the feature DAG from a Create file.
+
+    Parameters
+    ----------
+    input_path : str
+        Path to the ``.kc`` or ``.FCStd`` file.
+    output_path : str
+        Path to write the JSON output.
+
+    Output JSON::
+
+        {"nodes": [...], "edges": [...]}
+    """
+    from dag import extract_dag
+
+    doc = FreeCAD.openDocument(input_path)
+    try:
+        nodes, edges = extract_dag(doc)
+        with open(output_path, "w") as f:
+            json.dump({"nodes": nodes, "edges": edges}, f)
+        FreeCAD.Console.PrintMessage(
+            f"DAG extracted: {len(nodes)} nodes, {len(edges)} edges -> {output_path}\n"
+        )
+    finally:
+        FreeCAD.closeDocument(doc.Name)
+
+
+def validate(input_path, output_path):
+    """Validate a Create file by rebuilding all features.
+
+    Parameters
+    ----------
+    input_path : str
+        Path to the ``.kc`` or ``.FCStd`` file.
+    output_path : str
+        Path to write the JSON output.
+
+    Output JSON::
+
+        {
+            "valid": true/false,
+            "nodes": [
+                {"node_key": "Pad001", "state": "clean", "message": null, "properties_hash": "..."},
+                ...
+            ]
+        }
+    """
+    from dag import classify_type, compute_properties_hash
+
+    doc = FreeCAD.openDocument(input_path)
+    try:
+        doc.recompute()
+
+        results = []
+        all_valid = True
+
+        for obj in doc.Objects:
+            if not hasattr(obj, "TypeId"):
+                continue
+            node_type = classify_type(obj.TypeId)
+            if node_type is None:
+                continue
+
+            state = "clean"
+            message = None
+            if hasattr(obj, "isValid") and not obj.isValid():
+                state = "failed"
+                message = f"Feature {obj.Label} failed to recompute"
+                all_valid = False
+
+            results.append(
+                {
+                    "node_key": obj.Name,
+                    "state": state,
+                    "message": message,
+                    "properties_hash": compute_properties_hash(obj),
+                }
+            )
+
+        with open(output_path, "w") as f:
+            json.dump({"valid": all_valid, "nodes": results}, f)
+
+        status = "PASS" if all_valid else "FAIL"
+        FreeCAD.Console.PrintMessage(
+            f"Validation {status}: {len(results)} nodes -> {output_path}\n"
+        )
+    finally:
+        FreeCAD.closeDocument(doc.Name)
+
+
+def export(input_path, output_path, format="step"):
+    """Export a Create file to an external geometry format.
+
+    Parameters
+    ----------
+    input_path : str
+        Path to the ``.kc`` or ``.FCStd`` file.
+    output_path : str
+        Path to write the exported file.
+    format : str
+        One of ``step``, ``iges``, ``stl``, ``obj``.
+    """
+    import Part
+
+    doc = FreeCAD.openDocument(input_path)
+    try:
+        shapes = [
+            obj.Shape for obj in doc.Objects if hasattr(obj, "Shape") and obj.Shape
+        ]
+        if not shapes:
+            raise ValueError("No geometry found in document")
+
+        compound = Part.makeCompound(shapes)
+
+        format_lower = format.lower()
+        if format_lower == "step":
+            compound.exportStep(output_path)
+        elif format_lower == "iges":
+            compound.exportIges(output_path)
+        elif format_lower == "stl":
+            import Mesh
+
+            Mesh.export([compound], output_path)
+        elif format_lower == "obj":
+            import Mesh
+
+            Mesh.export([compound], output_path)
+        else:
+            raise ValueError(f"Unsupported format: {format}")
+
+        FreeCAD.Console.PrintMessage(
+            f"Exported {format_lower.upper()} -> {output_path}\n"
+        )
+    finally:
+        FreeCAD.closeDocument(doc.Name)