Isolate nested IPC sockets and define session ownership policy

compositor/src/xwayland/child.rs

@@ -349,6 +349,8 @@ mod tests {
 
     fn environment() -> SessionEnvironment {
         SessionEnvironment {
+            control_socket: std::path::PathBuf::from("/run/user/1000/ferese/control.sock"),
+            policy: crate::SessionPolicy::Desktop,
             wayland_display: OsString::from("wayland-7"),
             x11: None,
         }

compositor/src/xwayland/integration_tests.rs

@@ -90,6 +90,8 @@ impl Fixture {
 
     fn environment(&self) -> SessionEnvironment {
         SessionEnvironment {
+            control_socket: PathBuf::from("/run/user/1000/ferese/control.sock"),
+            policy: crate::SessionPolicy::Desktop,
             wayland_display: std::ffi::OsString::from("wayland-it"),
             x11: Some(X11Environment {
                 display: std::ffi::OsString::from(self.reservation.display_name()),