feat: add workflow run dispatch foundation

backend/app/domains/rendering/dispatch_service.py

@@ -13,7 +13,6 @@ task-dispatch logic in app.services.render_dispatcher (legacy path).
 from __future__ import annotations
 
 import logging
-from datetime import datetime
 
 logger = logging.getLogger(__name__)
 
@@ -32,7 +31,9 @@ def dispatch_render_with_workflow(order_line_id: str) -> dict:
 
     from app.config import settings
     from app.domains.orders.models import OrderLine
-    from app.domains.rendering.models import OutputType, WorkflowDefinition, WorkflowRun
+    from app.domains.rendering.models import OutputType, WorkflowDefinition
+    from app.domains.rendering.workflow_executor import prepare_workflow_context
+    from app.domains.rendering.workflow_run_service import create_workflow_run, mark_workflow_run_failed
 
     engine = create_engine(
         settings.database_url.replace("+asyncpg", ""),
@@ -96,6 +97,22 @@ def dispatch_render_with_workflow(order_line_id: str) -> dict:
             workflow_type,
         )
 
+        try:
+            workflow_context = prepare_workflow_context(
+                wf_def.config,
+                context_id=order_line_id,
+                execution_mode="legacy",
+            )
+        except Exception as exc:
+            logger.warning(
+                "order_line %s: workflow_definition_id %s failed runtime preparation (%s), "
+                "falling back to legacy dispatch",
+                order_line_id,
+                wf_def.id,
+                exc,
+            )
+            return _legacy_dispatch(order_line_id)
+
         # For turntable workflows: resolve step_path + output_dir from the order line at runtime
         if workflow_type == "turntable" and ("step_path" not in params or "output_dir" not in params):
             from app.domains.products.models import CadFile as _CadFile
@@ -120,19 +137,43 @@ def dispatch_render_with_workflow(order_line_id: str) -> dict:
                         str(_Path(_cfg.upload_dir) / "renders" / str(line.id)),
                     )
 
-        from app.domains.rendering.workflow_builder import dispatch_workflow
-        celery_task_id = dispatch_workflow(workflow_type, order_line_id, params)
+        run = None
+        try:
+            run = create_workflow_run(
+                session,
+                workflow_def_id=wf_def.id,
+                order_line_id=line.id,
+                workflow_context=workflow_context,
+            )
+            session.commit()
+        except Exception as exc:
+            session.rollback()
+            logger.warning(
+                "order_line %s: failed to create workflow run for workflow_definition_id %s (%s), "
+                "falling back to legacy dispatch",
+                order_line_id,
+                wf_def.id,
+                exc,
+            )
+            return _legacy_dispatch(order_line_id)
 
-        # Persist a WorkflowRun record
-        run = WorkflowRun(
-            workflow_def_id=wf_def.id,
-            order_line_id=line.id,
-            celery_task_id=celery_task_id,
-            status="pending",
-            started_at=datetime.utcnow(),
-        )
-        session.add(run)
-        session.commit()
+        from app.domains.rendering.workflow_builder import dispatch_workflow
+
+        try:
+            celery_task_id = dispatch_workflow(workflow_type, order_line_id, params)
+            run.celery_task_id = celery_task_id
+            session.commit()
+        except Exception as exc:
+            session.rollback()
+            session.add(run)
+            mark_workflow_run_failed(run, str(exc))
+            session.commit()
+            logger.exception(
+                "order_line %s: workflow dispatch via definition %s failed, falling back to legacy dispatch",
+                order_line_id,
+                wf_def.id,
+            )
+            return _legacy_dispatch(order_line_id)
 
         return {
             "backend": "workflow",