fix(browser): park webviews permanently paintable

Delete the renderer capture prep handshake and keep screenshots on the serialized invalidate/retry path. The capture harness now defaults to the production P1 attach-off parking check.

packages/app/src/desktop/host.ts

@@ -121,10 +121,6 @@ export interface DesktopBrowserShortcutEvent {
   action: "focus-url";
 }
 
-export interface DesktopBrowserPixelCapturePreparation {
-  token: string;
-}
-
 export interface DesktopBrowserNewTabRequestEvent {
   sourceBrowserId: string;
   url: string;
@@ -148,18 +144,6 @@ export interface DesktopBrowserBridge {
   ) => Promise<string | null>;
   /** Copy element text and/or an image to the system clipboard from main. */
   copyElement?: (payload: { text?: string; imageDataUrl?: string }) => Promise<boolean>;
-  onPrepareForPixelCapture?: (
-    handler: (input: {
-      requestId: string;
-      browserId: string;
-    }) => Promise<DesktopBrowserPixelCapturePreparation>,
-  ) => () => void;
-  onRestorePixelCapture?: (
-    handler: (input: DesktopBrowserPixelCapturePreparation) => Promise<void>,
-  ) => () => void;
-  onCancelPixelCapture?: (
-    handler: (input: { requestId?: string; token?: string }) => Promise<void>,
-  ) => () => void;
 }
 
 export interface DesktopInvokeBridge {