fix: old workspace migration (#14403)

fix #14395 

#### PR Dependency Tree


* **PR #14403** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
  * Added ability to enumerate and list local workspaces.
* Improved workspace ID persistence with Electron global-state storage,
automatic fallback to legacy storage, and one-time migration to
consolidate IDs.
* **Tests**
* Added unit test validating listing behavior (includes/excludes
workspaces based on presence of workspace DB file).
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/apps/electron/src/helper/workspace/handlers.ts

@@ -15,6 +15,7 @@ import { WorkspaceSQLiteDB } from '../nbstore/v1/workspace-db-adapter';
 import type { WorkspaceMeta } from '../type';
 import {
   getDeletedWorkspacesBasePath,
+  getSpaceBasePath,
   getSpaceDBPath,
   getWorkspaceBasePathV1,
   getWorkspaceMeta,
@@ -96,6 +97,33 @@ export async function storeWorkspaceMeta(
   }
 }
 
+export async function listLocalWorkspaceIds(): Promise<string[]> {
+  const localWorkspaceBasePath = path.join(
+    await getSpaceBasePath('workspace'),
+    'local'
+  );
+  if (!(await fs.pathExists(localWorkspaceBasePath))) {
+    return [];
+  }
+
+  const entries = await fs.readdir(localWorkspaceBasePath);
+  const ids = await Promise.all(
+    entries.map(async entry => {
+      const workspacePath = path.join(localWorkspaceBasePath, entry);
+      const stat = await fs.stat(workspacePath).catch(() => null);
+      if (!stat?.isDirectory()) {
+        return null;
+      }
+      if (!(await fs.pathExists(path.join(workspacePath, 'storage.db')))) {
+        return null;
+      }
+      return entry;
+    })
+  );
+
+  return ids.filter((id): id is string => typeof id === 'string');
+}
+
 type WorkspaceDocMeta = {
   id: string;
   name: string;

packages/frontend/apps/electron/src/helper/workspace/index.ts

@@ -3,6 +3,7 @@ import {
   deleteBackupWorkspace,
   deleteWorkspace,
   getDeletedWorkspaces,
+  listLocalWorkspaceIds,
   trashWorkspace,
 } from './handlers';
 
@@ -18,4 +19,5 @@ export const workspaceHandlers = {
     return getDeletedWorkspaces();
   },
   deleteBackupWorkspace: async (id: string) => deleteBackupWorkspace(id),
+  listLocalWorkspaceIds: async () => listLocalWorkspaceIds(),
 };