feat: workflow graph system — blocks 1-20 complete checkpoint

Full graph-based workflow execution engine with:
- WorkflowGraphRuntime with two-phase dispatch (collect → fire Celery tasks)
- Node registry with contract validation, socket types, execution kinds
- WorkflowRuntimeServices: preflight, context resolution, shadow-mode A/B
- WorkflowRouter: CRUD + dispatch/preflight/run-history API endpoints
- OutputTypeContracts: workflow binding, rollout-mode resolution
- Admin router: output-type workflow binding endpoints
- Frontend: complete workflow editor with drag-drop canvas, node inspector,
  module bundles, reference bundles, preflight panel, validation banner,
  authoring guidance, blueprint templates, shadow/rollout gate UI
- Tests: comprehensive coverage for all workflow modules
- Docs: NODE_CONTRACT_AUDIT and VALIDATION_ERROR_INVENTORY

All 20 blocks from NEXT_20_BLOCK_BATCH_PLAN completed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/domains/rendering/workflow_graph_runtime.py

@@ -142,6 +142,44 @@ _THUMBNAIL_TASK_KEYS = {
     "transparent_bg",
 }
 
+_RESOLVE_TEMPLATE_RUNTIME_KEYS = {
+    "template_id_override",
+    "material_library_path",
+    "require_template",
+    "disable_materials",
+    "target_collection",
+    "material_replace_mode",
+    "lighting_only_mode",
+    "shadow_catcher_mode",
+    "camera_orbit_mode",
+}
+
+_MATERIAL_MAP_RUNTIME_KEYS = {
+    "material_override",
+    "disable_materials",
+}
+
+_AUTO_POPULATE_RUNTIME_KEYS = {
+    "persist_updates",
+    "refresh_material_source",
+    "include_populated_products",
+}
+
+_GLB_BBOX_RUNTIME_KEYS = {
+    "glb_path",
+    "source_preference",
+}
+
+_OUTPUT_SAVE_RUNTIME_KEYS = {
+    "expected_artifact_role",
+    "require_upstream_artifact",
+}
+
+_NOTIFY_RUNTIME_KEYS = {
+    "channel",
+    "require_armed_render",
+}
+
 _AUTHORITATIVE_RENDER_SETTING_KEYS = {
     "render_engine",
     "engine",
@@ -1135,16 +1173,25 @@ def _execute_glb_bbox(
     node_params: dict[str, Any],
 ) -> tuple[dict[str, Any], str, str | None]:
     del node
-    del session, workflow_context
-    if state.setup is None or state.setup.cad_file is None:
-        if state.setup is not None and state.setup.status == "skip":
-            return _serialize_setup_result(state.setup), "skipped", state.setup.reason
-        raise WorkflowGraphRuntimeError("glb_bbox requires a resolved cad_file")
+    cad_file: CadFile | None = None
+    glb_path = node_params.get("glb_path")
 
-    step_path = state.setup.cad_file.stored_path
+    if state.setup is not None and state.setup.cad_file is not None:
+        if state.setup.status == "skip":
+            return _serialize_setup_result(state.setup), "skipped", state.setup.reason
+        cad_file = state.setup.cad_file
+    else:
+        cad_file = _resolve_cad_file_context(session, workflow_context, state)
+
+    step_path = cad_file.stored_path
     glb_path = node_params.get("glb_path")
     source_preference = str(node_params.get("source_preference") or "auto")
-    if glb_path is None and source_preference != "step_only" and state.setup.glb_reuse_path is not None:
+    if (
+        glb_path is None
+        and source_preference != "step_only"
+        and state.setup is not None
+        and state.setup.glb_reuse_path is not None
+    ):
         glb_path = str(state.setup.glb_reuse_path)
     elif glb_path is None and source_preference != "step_only":
         step_file = Path(step_path)