Add Windows desktop app menu (#28420)

packages/app/src/context/platform.tsx

@@ -1,6 +1,7 @@
 import { createSimpleContext } from "@opencode-ai/ui/context"
 import type { AsyncStorage, SyncStorage } from "@solid-primitives/storage"
 import type { Accessor } from "solid-js"
+import type { DesktopMenuAction } from "../desktop-menu"
 import { ServerConnection } from "./server"
 
 type PickerPaths = string | string[] | null
@@ -82,6 +83,9 @@ export type Platform = {
   /** Webview zoom level (desktop only) */
   webviewZoom?: Accessor<number>
 
+  /** Run a desktop-only menu action from the app chrome */
+  runDesktopMenuAction?(action: DesktopMenuAction): Promise<void> | void
+
   /** Check if an editor app exists (desktop only) */
   checkAppExists?(appName: string): Promise<boolean>