app-server support for Windows sandbox setup. (#12025)

app-server support for initiating Windows sandbox setup.
server responds quickly to setup request and makes a future RPC call
back to client when the setup finishes.

The TUI implementation is unaffected but in a future PR I'll update the
TUI to use the shared setup helper
(`windows_sandbox.run_windows_sandbox_setup`)

codex-rs/app-server-protocol/src/protocol/common.rs

@@ -309,6 +309,11 @@ client_request_definitions! {
         response: v2::ListMcpServerStatusResponse,
     },
 
+    WindowsSandboxSetupStart => "windowsSandbox/setupStart" {
+        params: v2::WindowsSandboxSetupStartParams,
+        response: v2::WindowsSandboxSetupStartResponse,
+    },
+
     LoginAccount => "account/login/start" {
         params: v2::LoginAccountParams,
         inspect_params: true,
@@ -805,6 +810,7 @@ server_notification_definitions! {
 
     /// Notifies the user of world-writable directories on Windows, which cannot be protected by the sandbox.
     WindowsWorldWritableWarning => "windows/worldWritableWarning" (v2::WindowsWorldWritableWarningNotification),
+    WindowsSandboxSetupCompleted => "windowsSandbox/setupCompleted" (v2::WindowsSandboxSetupCompletedNotification),
 
     #[serde(rename = "account/login/completed")]
     #[ts(rename = "account/login/completed")]