dashboard: remove peer-hives headline block (hyperhive#3294)

Removes the SW4RM tab's "P33R H1V3S" headline section
(#peers-block/#peers-section in dashboard.html, renderPeerHives in
swarm.js, its call site + import in tabs.js). Superseded by swarm-ui's
own hive roster page.

Verified: npm run build clean (would have failed to resolve
renderPeerHives if the import/export pair were left mismatched).

frontend/packages/dashboard/src/tabs.js

@@ -46,7 +46,7 @@ import {
   applyRebuildQueueChanged, applyContainerStateChanged, applyContainerRemoved,
   applyTransientSet, applyTransientCleared,
   renderContainers, renderContainersFromState,
-  renderSelectionBar, renderPeerHives,
+  renderSelectionBar,
 } from './swarm.js';
 
 // mdNode (in common.js) reads `window.marked` for the markdown side
@@ -201,9 +201,6 @@ window.marked = marked;
       // synchronous read (e.g. the compose autocomplete pulls agent
       // names from here instead of refetching on every keystroke).
       window.__hyperhive_state = s;
-      // Peer hives render as a headline section under SW4RM (no longer
-      // a tab); renderPeerHives shows/hides its own headline block.
-      renderPeerHives(s.peer_hives || []);
       renderServerWarnings(s.server_warnings);
       // (The M4TR1X surface is reachable from the H0M3 hub now, not the
       // dashboard tab strip — home.js gates its tile on matrix_gui_enabled.)