fix: 修复 buddy 命令 ESC 关闭后进入永久 loading 状态

CancelRequestHandler 先于 BuddyPanel 的 ESC handler 拦截按键，
仅清除面板但未 resolve processSlashCommand 中的 Promise，
导致 queryGuard 卡在 dispatching 状态。通过在 setToolJSX
中增加 onDismiss 回调，在面板被外部清除时同步 resolve Promise。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/Tool.ts

@@ -112,6 +112,9 @@ export type SetToolJSXFn = (
     isImmediate?: boolean
     /** Set to true to clear a local JSX command (e.g., from its onDone callback) */
     clearLocalJSX?: boolean
+    /** Called when the panel is dismissed externally (e.g. ESC via CancelRequestHandler).
+     * Must resolve the underlying Promise in processSlashCommand.tsx. */
+    onDismiss?: () => void
   } | null,
 ) => void