refactor: unify agent session persistence

src/utils/fileStore.ts

@@ -20,7 +20,7 @@ export const atomicWriteFile = async (path: string, content: string) => {
 
 type HistoricalWriteOptions = {
   afterWrite?: () => Promise<void> | void;
-  historyDir: string;
+  backupDir: string;
   rootDir: string;
 };
 
@@ -36,8 +36,8 @@ export const atomicWriteFileWithHistory = async (
 
   let backupPath: string | null = null;
   if (previous !== null) {
-    // 仅在覆盖已有文件时保留历史版本，避免为首次创建产生空备份。
-    backupPath = buildHistoryBackupPath(path, options);
+    // 仅在覆盖已有文件时保留备份版本，避免为首次创建产生空备份。
+    backupPath = buildBackupPath(path, options);
     await atomicWriteFile(backupPath, previous);
   }
 
@@ -149,12 +149,6 @@ export const toProjectKey = (projectId?: string) => toScopedKey("project", proje
 export const toStableId = (...parts: string[]) =>
   createHash("sha256").update(parts.join("|")).digest("hex").slice(0, 24);
 
-export const toConversationScopeKey = (
-  actorKey: string,
-  projectKey: string,
-  sessionId: string,
-) => `conversation-${toStableId(actorKey, projectKey, sessionId)}`;
-
 export const slugify = (value: string) =>
   value
     .toLowerCase()
@@ -162,11 +156,11 @@ export const slugify = (value: string) =>
     .replace(/^-+|-+$/g, "")
     .slice(0, 64) || "entry";
 
-const buildHistoryBackupPath = (path: string, options: HistoricalWriteOptions) => {
+const buildBackupPath = (path: string, options: HistoricalWriteOptions) => {
   const relativePath = relative(options.rootDir, path);
   const scopedPath =
     relativePath && !relativePath.startsWith("..") ? relativePath : basename(path);
   // 备份目录尽量复用原始相对路径，便于按业务目录回看历史。
   const backupName = `${basename(path)}.${Date.now().toString(36)}.bak`;
-  return join(options.historyDir, dirname(scopedPath), backupName);
+  return join(options.backupDir, dirname(scopedPath), backupName);
 };