Step 323: Workflow Sidecar Persistence (12/12 tests)

Save/load workflow state to .whetstone/<project>.workflow.json with
directory creation, overwrite, delete, and multi-workflow support.

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

editor/src/WorkflowPersistence.h

@@ -0,0 +1,108 @@
+#pragma once
+// Step 323: Workflow Sidecar Persistence
+//
+// Save and load workflow state to .whetstone/<project>.workflow.json
+// so workflows survive across sessions.
+
+#include "WorkflowState.h"
+#include <string>
+#include <optional>
+#include <fstream>
+#include <sstream>
+#include <sys/stat.h>
+
+// --- SaveResult ---
+
+struct SaveResult {
+    bool success = false;
+    std::string path;
+    int bytesWritten = 0;
+    int itemCount = 0;
+};
+
+// --- Path helper ---
+
+inline std::string workflowSidecarPath(const std::string& workspaceRoot,
+                                        const std::string& projectName) {
+    return workspaceRoot + "/.whetstone/" + projectName + ".workflow.json";
+}
+
+// --- Create parent directories recursively ---
+
+inline bool ensureDirectoryExists(const std::string& path) {
+    // Find last slash to get directory
+    auto pos = path.rfind('/');
+    if (pos == std::string::npos) return true;
+    std::string dir = path.substr(0, pos);
+
+    // Simple recursive mkdir
+    std::string current;
+    for (size_t i = 0; i < dir.size(); ++i) {
+        current += dir[i];
+        if (dir[i] == '/' || i == dir.size() - 1) {
+            mkdir(current.c_str(), 0755);
+        }
+    }
+    // Check if directory exists
+    struct stat st{};
+    return stat(dir.c_str(), &st) == 0 && S_ISDIR(st.st_mode);
+}
+
+// --- Save workflow ---
+
+inline SaveResult saveWorkflow(const std::string& workspaceRoot,
+                                const WorkflowState& state) {
+    SaveResult result;
+    result.path = workflowSidecarPath(workspaceRoot, state.projectName);
+
+    if (!ensureDirectoryExists(result.path)) {
+        return result;
+    }
+
+    json j = state.toJson();
+    std::string content = j.dump(2);
+
+    std::ofstream ofs(result.path);
+    if (!ofs.is_open()) return result;
+
+    ofs << content;
+    ofs.close();
+
+    if (ofs.fail()) return result;
+
+    result.success = true;
+    result.bytesWritten = static_cast<int>(content.size());
+    result.itemCount = state.queue.size();
+    return result;
+}
+
+// --- Load workflow ---
+
+inline std::optional<WorkflowState> loadWorkflow(const std::string& workspaceRoot,
+                                                  const std::string& projectName) {
+    std::string path = workflowSidecarPath(workspaceRoot, projectName);
+
+    std::ifstream ifs(path);
+    if (!ifs.is_open()) return std::nullopt;
+
+    std::ostringstream oss;
+    oss << ifs.rdbuf();
+    std::string content = oss.str();
+
+    if (content.empty()) return std::nullopt;
+
+    try {
+        json j = json::parse(content);
+        return WorkflowState::fromJson(j);
+    } catch (...) {
+        return std::nullopt;
+    }
+}
+
+// --- Delete workflow ---
+
+inline bool deleteWorkflow(const std::string& workspaceRoot,
+                            const std::string& projectName) {
+    std::string path = workflowSidecarPath(workspaceRoot, projectName);
+    return std::remove(path.c_str()) == 0;
+}