fix(tui): use WinRT clipboard API on Windows (anomalyco#15951)

Cherry-picked from upstream PR anomalyco#15951.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Author: IgorTavcar

packages/opencode/src/cli/cmd/tui/util/clipboard.ts

@@ -126,7 +126,7 @@ export namespace Clipboard {
     }
 
     if (os === "win32") {
-      console.log("clipboard: using powershell")
+      console.log("clipboard: using windows runtime")
       return async (text: string) => {
         // Pipe via stdin to avoid PowerShell string interpolation ($env:FOO, $(), etc.)
         const proc = Process.spawn(
@@ -135,7 +135,7 @@ export namespace Clipboard {
             "-NonInteractive",
             "-NoProfile",
             "-Command",
-            "[Console]::InputEncoding = [System.Text.Encoding]::UTF8; Set-Clipboard -Value ([Console]::In.ReadToEnd())",
+            "[Console]::InputEncoding = [System.Text.Encoding]::UTF8; $null = [Windows.ApplicationModel.DataTransfer.DataPackage, Windows.ApplicationModel.DataTransfer, ContentType=WindowsRuntime]; $null = [Windows.ApplicationModel.DataTransfer.Clipboard, Windows.ApplicationModel.DataTransfer, ContentType=WindowsRuntime]; $pkg = New-Object Windows.ApplicationModel.DataTransfer.DataPackage; $pkg.SetText([Console]::In.ReadToEnd()); [Windows.ApplicationModel.DataTransfer.Clipboard]::SetContent($pkg); [Windows.ApplicationModel.DataTransfer.Clipboard]::Flush()",
           ],
           {
             stdin: "pipe",