For stand-alone version, the data in the db directory is not cleared after restart

**Bug Description**
For stand-alone version, the data in the db directory is not cleared after restart.

After the stand-alone version is restarted, the data is cleared, and the data in the same db directory should also be cleared

**Expected Behavior**

**Steps to Reproduce**

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The issue mentions a 'db directory' not being cleared on restart of the stand-alone version. Look for code handling data persistence and cleanup in the stand-alone mode, likely in storage or initialization modules. Check how the database directory is managed on startup and shutdown. Determine what 'cleared' means—whether it's deleting files or resetting in-memory state—and verify the expected behavior against the current implementation.

Written by the indexing model from the issue text.