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_router.py

@@ -105,7 +105,6 @@ _ORDER_LINE_SETUP_REQUIRED_STEPS = {
     StepName.RESOLVE_TEMPLATE,
     StepName.MATERIAL_MAP_RESOLVE,
     StepName.AUTO_POPULATE_MATERIALS,
-    StepName.GLB_BBOX,
     StepName.BLENDER_STILL,
     StepName.BLENDER_TURNTABLE,
     StepName.OUTPUT_SAVE,
@@ -322,6 +321,23 @@ def _format_order_line_context_label(order: Order, line: OrderLine) -> tuple[str
     )
 
 
+def _get_order_line_context_renderability(
+    order: Order,
+    line: OrderLine,
+    *,
+    allow_completed_order_rerender: bool = False,
+) -> tuple[bool, str | None]:
+    if line.render_status == "cancelled":
+        return False, "line_cancelled"
+    if order.status == OrderStatus.rejected:
+        return False, "order_closed"
+    if order.status == OrderStatus.completed and not allow_completed_order_rerender:
+        return False, "order_closed"
+    if line.product is None or line.product.cad_file_id is None:
+        return False, "missing_cad_file"
+    return True, None
+
+
 def _issue(
     severity: str,
     code: str,
@@ -350,6 +366,16 @@ def _node_status(issues: list[WorkflowPreflightIssueOut], *, supported: bool) ->
 
 
 def _infer_expected_context_kind(ordered_nodes: list) -> str:
+    concrete_families = {
+        definition.family
+        for node in ordered_nodes
+        if (definition := get_node_definition(node.step)) is not None
+        and definition.family in {"cad_file", "order_line"}
+    }
+    if concrete_families == {"order_line"}:
+        return "order_line"
+    if concrete_families == {"cad_file"}:
+        return "cad_file"
     if any(node.step in _ORDER_LINE_RUNTIME_STEPS for node in ordered_nodes):
         return "order_line"
     return "cad_file"
@@ -444,7 +470,12 @@ def _build_workflow_preflight_for_config(
         )
 
     if context_kind == "order_line" and order_line is not None:
-        setup = prepare_order_line_render_context(session, str(order_line.id), persist_state=False)
+        setup = prepare_order_line_render_context(
+            session,
+            str(order_line.id),
+            persist_state=False,
+            allow_completed_order_rerender=True,
+        )
         if setup.order_line is not None:
             resolved_order_line_id = setup.order_line.id
         if setup.cad_file is not None:
@@ -567,6 +598,35 @@ def _build_workflow_preflight_for_config(
                     )
                 )
 
+        if node.step == StepName.GLB_BBOX and context_kind == "order_line":
+            setup_indices = [
+                node_indices[candidate.id]
+                for candidate in workflow_context.ordered_nodes
+                if candidate.step == StepName.ORDER_LINE_SETUP
+            ]
+            has_prior_setup = any(index < node_indices[node.id] for index in setup_indices)
+            if not has_prior_setup:
+                node_issues.append(
+                    _issue(
+                        "error",
+                        "missing_order_line_setup",
+                        "This node requires an earlier order_line_setup node when used with an order-line context.",
+                        node_id=node.id,
+                        step=node.step.value,
+                    )
+                )
+            elif setup is None or not setup.is_ready:
+                reason = setup.reason if setup is not None else "order_line_setup_not_executed"
+                node_issues.append(
+                    _issue(
+                        "error",
+                        "setup_not_ready",
+                        f"Order-line setup is not ready for this node: {reason}.",
+                        node_id=node.id,
+                        step=node.step.value,
+                    )
+                )
+
         if node.step in _RESOLVE_TEMPLATE_RECOMMENDED_STEPS:
             template_indices = [
                 node_indices[candidate.id]
@@ -763,15 +823,23 @@ async def list_workflow_order_line_contexts(
         options: list[WorkflowOrderLineContextOptionOut] = []
         for line in order.lines:
             label, meta = _format_order_line_context_label(order, line)
+            is_renderable, renderability_reason = _get_order_line_context_renderability(
+                order,
+                line,
+                allow_completed_order_rerender=True,
+            )
             options.append(
                 WorkflowOrderLineContextOptionOut(
                     value=line.id,
                     label=label,
                     meta=meta,
+                    is_renderable=is_renderable,
+                    renderability_reason=renderability_reason,
                 )
             )
 
         if options:
+            options.sort(key=lambda option: (not option.is_renderable, option.label.lower()))
             groups.append(
                 WorkflowOrderLineContextGroupOut(
                     order_id=order.id,
@@ -780,6 +848,12 @@ async def list_workflow_order_line_contexts(
                 )
             )
 
+    groups.sort(
+        key=lambda group: (
+            not any(option.is_renderable for option in group.options),
+            group.order_label.lower(),
+        )
+    )
     return groups
 
 
@@ -948,7 +1022,10 @@ async def _dispatch_workflow_for_config(
     workflow_config: dict,
     context_id: str,
 ) -> WorkflowDispatchResponse:
-    from app.domains.rendering.workflow_executor import prepare_workflow_context
+    from app.domains.rendering.workflow_executor import (
+        prepare_workflow_context,
+        submit_prepared_workflow_tasks,
+    )
     from app.domains.rendering.workflow_graph_runtime import execute_graph_workflow
     from app.domains.rendering.workflow_run_service import (
         create_workflow_run,