feat(dashboard): add 'journal logs →' link to agent overflow menu

Adds a navigation entry in the per-agent ⋮ overflow menu that opens the
AGENT log tab pre-filtered to that container. The link uses the ?agent= URL
param introduced by the accompanying logs.js change — the operator lands
directly in the journal viewer without having to pick an agent from the
dropdown.

Placed between the rebuild action and the destructive destroy/purge block
so it's reachable but clearly separated from dangerous actions.

frontend/packages/dashboard/src/tabs.js

@@ -426,6 +426,20 @@ window.marked = marked;
       return el('li', { class: 'agent-menu-sep', role: 'separator' });
     }
 
+    // Navigation link item (opens in same tab by default).
+    function menuLink(label, href, title) {
+      const li = el('li', { role: 'presentation' });
+      const a = el('a', {
+        class: 'agent-menu-item',
+        href,
+        role: 'menuitem',
+        title: title || '',
+      }, label);
+      a.addEventListener('click', () => closeAllAgentMenus());
+      li.append(a);
+      return li;
+    }
+
     // Show only actions that are applicable in the current state.
     if (c.running) {
       dropdown.append(
@@ -439,6 +453,14 @@ window.marked = marked;
     }
     dropdown.append(
       menuItem('↻ R3BU1LD', { action: '/rebuild/', confirm: `rebuild ${c.name}? hot-reloads the container.` }),
+      menuSep(),
+      // Deep-link to the AGENT log tab pre-filtered to this container.
+      // The ?agent= param is read by logs.js on load; the stored localStorage
+      // selection is overridden so the operator lands directly in this
+      // agent's journal without extra clicks.
+      menuLink('journal logs →',
+        `/logs.html?agent=${encodeURIComponent(c.name)}#agent`,
+        `view ${c.name} journal logs`),
     );
 
     {