VS Code extension overwrites manually-renamed session titles

Summary: In the Claude Code VS Code side panel, manually renaming a session (chat thread) does not stick. After renaming and continuing the conversation, the extension auto-regenerates the title from the new topic, discarding my custom name.

Steps to reproduce:

1. Open a session in the VS Code Claude Code side panel.
2. Hover the session and rename it to a custom title.
3. Continue chatting in that session on a different/evolving topic.
4. The session title auto-changes back to an AI-generated name, overwriting my manual rename.

Expected: A manually-set session name should be treated as pinned/permanent and never auto-overwritten by topic-based title generation.

Actual: The manual name is replaced by a new auto-generated title as the conversation continues.

Environment: Claude Code VS Code extension v2.1.161, Windows 11.

Suggested fix: Once a session is manually renamed, suppress automatic re-titling for that session (or add a setting / lock indicator to opt out of auto-renaming).