Elevated Sandbox 3 (#7809)

dedicated sandbox command runner exe.

codex-rs/windows-sandbox-rs/src/bin/command_runner.rs

@@ -0,0 +1,12 @@
+#[path = "../command_runner_win.rs"]
+mod win;
+
+#[cfg(target_os = "windows")]
+fn main() -> anyhow::Result<()> {
+    win::main()
+}
+
+#[cfg(not(target_os = "windows"))]
+fn main() {
+    panic!("codex-command-runner is Windows-only");
+}