even MORE code review

stateful to not deadhang, graph context -> output, more explicit state errors, other misc changes idfk any of those good thing theyre fixed tho

src/wf_authoring/builder/core.py

@@ -207,7 +207,7 @@ class WorkflowBuilder:
     input_schema: SchemaLike
     state_schema: StateSchemaLike
     output_schema: SchemaLike
-    outcomes: Sequence[str] | None = None
+    outcomes: Sequence[str] = ("ok",)
     start: str | None = None
     reducers: ReducerCatalog | Mapping[str, ReducerDefinition] | None = None
     node_specs: dict[str, NodeSpec[Any, Any]] = field(default_factory=dict)
@@ -222,7 +222,6 @@ class WorkflowBuilder:
         self.input_schema = schema_ref_from(self.input_schema)
         self.state_schema = state_schema_from(self.state_schema)
         self.output_schema = schema_ref_from(self.output_schema)
-        self.outcomes = list(self.outcomes or ["ok"])
 
     @overload
     def use(
@@ -871,7 +870,7 @@ class WorkflowBuilder:
             input_schema=cast(SchemaRef, self.input_schema),
             state_schema=cast(StateSchema, self.state_schema),
             output_schema=cast(SchemaRef, self.output_schema),
-            outcomes=list(self.outcomes or ["ok"]),
+            outcomes=list(self.outcomes),
             node_defs=node_defs,
             start=self.start,
             nodes=self.nodes,

src/wf_core/runtime/foreach_state.py

@@ -363,8 +363,10 @@ def _state_write_from_metadata(raw: object) -> StateWrite:
             visible_value=visible_value,
             reducer=ReducerRef.model_validate(reducer),
         )
-    except Exception as exc:
-        raise WorkflowExecutionError("malformed pending foreach write") from exc
+    except WorkflowExecutionError:
+        raise
+    except (TypeError, ValueError) as exc:
+        raise WorkflowExecutionError(f"malformed pending foreach write: {exc}") from exc
 
 
 def _state_write_to_metadata(write: StateWrite) -> dict[str, Any]:

src/wf_core/runtime/lineage.py

@@ -216,7 +216,13 @@ def _lineage_chain(
 ) -> Iterator[LineageState]:
     lineage = _lineage(run, scope_id=scope_id, lineage_id=lineage_id)
     reverse_chain: list[LineageState] = []
+    seen: set[str] = set()
     while True:
+        if lineage.id in seen:
+            raise WorkflowExecutionError(
+                f"cycle detected in lineage chain at {lineage.id!r}"
+            )
+        seen.add(lineage.id)
         reverse_chain.append(lineage)
         if lineage.parent_id is None:
             break

src/wf_core/runtime/subgraphs.py

@@ -253,6 +253,7 @@ def _finish_subgraph(
         prepared.workflow,
         child_scope.committed_state,
         workflow_input=child_scope.workflow_input,
+        context=frame_context_values(child_frame),
     )
     validate_payload_against_schema(
         prepared.workflow.output_schema,

src/wf_mcp/runtime/factory.py

@@ -141,7 +141,7 @@ class _SessionOwner:
         tool_name: str,
         payload: dict[str, object],
     ) -> CallToolResult:
-        """Submit a tool call for execution in the transport owner task."""
+        """Submit a call and fail promptly if its transport owner exits."""
         task = self._task
         if task is None:
             raise RuntimeError("persistent MCP session is not started")
@@ -152,7 +152,13 @@ class _SessionOwner:
         await self._requests.put(
             _ToolCallRequest(tool_name=tool_name, payload=payload, result=result)
         )
-        return await result
+        done, _pending = await asyncio.wait(
+            {result, task}, return_when=asyncio.FIRST_COMPLETED
+        )
+        if result in done:
+            return result.result()
+        await task
+        raise RuntimeError("persistent MCP session stopped unexpectedly")
 
     async def close(self) -> None:
         """Ask the owner task to close the MCP transport in its own scope."""
@@ -187,5 +193,11 @@ class _SessionOwner:
         except BaseException as exc:
             if not ready.done():
                 ready.set_exception(exc)
-            else:
-                raise
+                return
+            # Calls already queued behind the failing request cannot otherwise
+            # observe that their sole transport owner has exited.
+            while not self._requests.empty():
+                pending = self._requests.get_nowait()
+                if pending is not None and not pending.result.done():
+                    pending.result.set_exception(exc)
+            raise

src/wf_mcp/workflow_surface/tools.py

@@ -604,8 +604,9 @@ def register_workflow_tools(server: FastMCP[Any], service: WfMcpService) -> None
         title="Run Workflow Deployment",
         description=(
             "Run deployment_id with workflow_input and return status, terminal "
-            "outcome, output, diagnostics, and trace_count. Debug traces can include resolved "
-            "inputs and state changes; pass trace_range only when needed."
+            "outcome when completed, output, diagnostics, and trace_count. "
+            "Debug traces can include resolved inputs and state changes; pass "
+            "trace_range only when needed."
         ),
     )
     async def run_deployment(