VSCode extension: switching open folder hides/loses session from sidebar list

Description

In the Claude Code VSCode extension, switching the open folder (workspace) in VSCode causes the sidebar session list to show only sessions tied to the new folder's path. Since sessions are stored per-working-directory under ~/.claude/projects/<encoded-path>/, opening a different folder makes the previous conversation appear to vanish completely — it's not in the session list, and there's no way to find it from the new folder context.

The underlying session files (.jsonl) are not lost, but there is no UI affordance to browse or resume sessions from other project folders without manually reopening that exact folder in VSCode.

Steps to reproduce

1. Open folder A in VSCode, start a Claude Code chat in the sidebar.
2. Without closing VSCode, use File → Open Folder to switch to folder B.
3. Open the Claude Code sidebar — the session from folder A is gone from the list (folder B's list is empty/different).
4. There is no in-UI way to see or resume the folder A session unless you reopen folder A specifically.

Expected behavior

At minimum, either:

• A way to view/search sessions across all project folders from the sidebar, not just the currently open one, or
• A clear indicator/switcher showing "sessions are scoped to this folder" with a quick way to browse other folders' sessions.

Actual behavior

The session list silently empties out with no indication that the previous session still exists elsewhere — it looks like data loss even though it isn't.

Environment

• OS: KDE neon (Ubuntu 24.04 based)
• Claude Code VSCode extension