VS Code extension: insertAtMention with multiple conversation tabs reveals a hidden session and steals focus

Environment

• Claude Code VS Code extension 2.1.220 (also observed on 2.1.219)
• VS Code 1.130.0 (commit 1b6a188127eeaf9194f945eb6eb89a657e93c54c), macOS (darwin arm64)

Steps to reproduce

1. Open several Claude Code conversations as editor tabs in one window (same tab group).
2. Focus a text editor and select a few lines.
3. Run "Claude Code: Insert @-Mention Reference" (claude-vscode.insertAtMention, default Option+K).

Observed

• The @file#N-M mention is inserted into the visible conversation's prompt (correct).
• But the Claude tab group then flips its active tab to a different, previously hidden conversation, and keyboard focus moves there. With multiple conversation tabs this happens on every invocation, and it consistently lands on a conversation the user was not working in.

Expected

The visible conversation receives the mention and stays active. Focus behavior should be predictable: either stay in the text editor or move to the conversation that received the mention - never to a different session.

Analysis (from reading the bundled extension.js)

• claude-vscode.insertAtMention fires one shared event carrying the mention text.
• Every open session subscribes to that event. On fire, each session sends insert_at_mention to its own webview and then, if it has a panel tab, calls this.panelTab.reveal() - with no arguments, so preserveFocus is false.
• Hidden sessions' webviews are suspended, so their inserts are harmless, but their reveal() still executes on the extension host side. The last reveal wins and flips the tab group to a hidden conversation.
• WebviewPanel.reveal() is a fire-and-forget $reveal RPC on the VS Code side (confirmed against the matching vscode source tag), so the tab flip lands asynchronously after the command completes. That also means a user-side runCommands chain cannot reliably undo it.

Suggested fix

Any of these would resolve it:

• Only the session that receives the mention (the visible / most recently active conversation) calls reveal().
• Skip reveal() for sessions whose webview is not visible.
• Call reveal() with preserveFocus: true (this still flips the visible tab, so the first two options are better).

Workaround in use

A small personal extension that snapshots each tab group's active tab, runs insertAtMention, polls until the reveal lands, and restores the previous state. It works, but the asynchronous reveal makes a visible flicker unavoidable, which is why an upstream fix would be appreciated.