Pin the real-vlt get_and_remove leg to --mode agent

`get <uuid>` defaults to hosted since v5, so the leg's in-place
patched/pristine assertions need agent mode spelled out.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PQaKzoW5dSw9u5pgAAvVRj

Author: claude

crates/socket-patch-cli/tests/e2e_vlt.rs

@@ -143,7 +143,7 @@ async fn vlt_pinned_matrix_agent_get_and_remove() {
         return;
     };
     let fx = Fixture::build(leg, Shape::with_bystander().warm()).await;
-    let out = socket_api(&fx.proj, &fx.svc, &["get", UUID], &[]);
+    let out = socket_api(&fx.proj, &fx.svc, &["get", UUID, "--mode", "agent"], &[]);
     assert_eq!(out.code, 0, "{out}");
     assert_eq!(state(&fx.proj, fx.t()), State::Patched);
     let purl = fx.t().purl();