Step 324: Workflow RPC + MCP Tools (12/12 tests)

8 new RPC methods and MCP tools for workflow lifecycle management:
create, inspect, assign, complete, reject, save. Role-based access
control enforced — Linter read-only, Refactor/Generator can mutate.

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

editor/src/HeadlessEditorState.h

@@ -37,6 +37,8 @@
 #include "SidecarPersistence.h"
 #include "AnnotationInference.h"
 #include "SkeletonAST.h"
+#include "WorkflowState.h"
+#include "WorkflowPersistence.h"
 
 #include <nlohmann/json.hpp>
 #include <string>
@@ -134,6 +136,7 @@ struct HeadlessEditorState {
     std::string          workspaceRoot;
     std::string          defaultLanguage = "python";
     bool                 verbose = false;
+    std::optional<WorkflowState> workflow;
 
     // --- Buffer access ---