Conversation title resets to first message after manual rename in VS Code extension

Description

In the VS Code extension, when a user manually renames a conversation, the title reverts back to the auto-generated title (derived from the first message) after refreshing or reopening VS Code.

Steps to Reproduce

1. Start a conversation in the Claude Code VS Code extension
2. Manually rename the conversation to a custom title
3. Refresh or reopen VS Code

Expected Behavior

The manually set title should persist.

Actual Behavior

The title resets back to the auto-generated title from the first message, making the rename feature effectively useless.

Impact

The rename feature is misleading — it appears to work but changes are not persisted. Either the rename should be persisted, or the edit option should be removed if it cannot be supported.