fix: remove stale cinematic legacy-only guard in dispatch_service

The guard forced all cinematic output types to legacy dispatch because
BLENDER_CINEMATIC did not exist in the workflow graph. M1 added that node,
so the guard is now stale — it was preventing cinematic output types from
ever using graph mode even after an admin sets workflow_rollout_mode=graph.

The normal gate path handles it correctly: workflow_rollout_mode=legacy_only
keeps it on legacy, and find_unsupported_graph_nodes preflight catches any
workflow that doesn't actually contain a BLENDER_CINEMATIC node.

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

backend/app/domains/rendering/dispatch_service.py

@@ -193,30 +193,6 @@ def dispatch_render_with_workflow(order_line_id: str) -> dict:
             )
             return legacy_result
 
-        # Cinematic output types have no BLENDER_CINEMATIC graph node — force legacy regardless
-        # of what workflow_rollout_mode or workflow_definition_id say.
-        if output_type and isinstance(output_type.render_settings, dict) and output_type.render_settings.get("cinematic"):
-            logger.warning(
-                "order_line %s: output_type %s is cinematic but has a workflow_definition_id set; "
-                "forcing legacy dispatch (no BLENDER_CINEMATIC node exists in the workflow graph)",
-                order_line_id,
-                output_type.id,
-            )
-            legacy_result = _legacy_dispatch(order_line_id)
-            legacy_result.update(
-                _build_rollout_signal(
-                    gate_status="cinematic_legacy_only",
-                    ready=False,
-                    reasons=[
-                        "Cinematic output types always use the legacy dispatch path.",
-                        "Remove the workflow_definition_id link to silence this warning.",
-                    ],
-                    workflow_def_id=wf_def.id,
-                    output_type_id=output_type.id,
-                )
-            )
-            return legacy_result
-
         configured_execution_mode = get_workflow_execution_mode(canonical_config, default="legacy")
         workflow_rollout_mode = _normalize_workflow_rollout_mode(
             getattr(output_type, "workflow_rollout_mode", None)