[VS Code] Alt+K should target only the active panel

Environment / 环境

• Kimi Code VS Code extension
• OS: macOS
• Multiple VS Code windows / panels open at the same time / 同时打开多个 VS Code 窗口或 Kimi Code 面板

Issue 1: Alt+K file reference should only go to the ACTIVE panel / Alt+K 添加文件时应只作用于当前活跃面板

When multiple Kimi Code windows/panels are open, pressing Alt+K to add the current file/selection does not reliably target the currently active panel.

多开 Kimi Code 窗口/面板时，按 Alt+K 添加当前选中的文件，不能保证只添加到当前活跃的那个 Kimi Code 窗口。

Expected / 期望: Alt+K should insert the file reference ONLY into the currently active (focused) Kimi Code panel. / 期望 Alt+K 只把文件引用插入当前活跃（获得焦点）的 Kimi Code 面板。

Issue 2: Alt+K reopens the hidden main panel instead of using the split panel / 主面板被隐藏时 Alt+K 会重新打开主面板

If a split (secondary) Kimi Code panel is open while the main Kimi Code panel is hidden, pressing Alt+K reopens the main panel.

如果已经分出了一个 Kimi Code 面板，而主的 Kimi Code 面板处于隐藏状态，按 Alt+K 会把主面板重新打开。

Expected / 期望: Do NOT reopen the hidden main panel — insert the file reference directly into the existing split panel. / 期望不要重新打开被隐藏的主面板，直接把文件地址添加到已分出的 Kimi Code 面板中即可。

Start by locating the VS Code Alt+K command and the panel-routing logic it invokes. Trace how the active or focused Kimi Code panel is selected when multiple windows or split panels exist, including when the main panel is hidden. Done means Alt+K inserts the reference only into the active existing panel and does not reopen the hidden main panel.