fix(#1096): remove container name/port chip from dashboard card

Drop the 'h-sock :8421' meta span from the agent card head.
ContainerView.container is now #[serde(skip)] since no frontend
code reads it; the field stays in Rust for internal use.
c.port remains serialized — used for fallback agent UI URLs.

frontend/packages/dashboard/src/tabs.js

@@ -779,7 +779,6 @@ window.marked = marked;
           {}, { noRefresh: true },
         ));
       }
-      head.append(el('span', { class: 'meta' }, `${c.container} :${c.port}`));
       if (c.deployed_sha) {
         head.append(el('span',
           { class: 'meta', title: 'sha currently locked in /meta/flake.lock' },