fix(988): hide inapplicable actions in agent context menu

Per mara feedback: don't show disabled actions at all.
- restart/stop only rendered when agent is running
- start only rendered when agent is stopped
- removed .agent-menu-item:disabled CSS rule (no longer needed)

Also switch Escape handler to stopImmediatePropagation so the
selection-clear keydown listener doesn't co-fire when closing a menu.

frontend/packages/dashboard/src/dashboard.css

@@ -384,13 +384,9 @@ a:hover {
   padding: 0.4em 0.9em;
   cursor: pointer;
 }
-.agent-menu-item:not(:disabled):hover {
+.agent-menu-item:hover {
   background: var(--surface1);
 }
-.agent-menu-item:disabled {
-  opacity: 0.35;
-  cursor: default;
-}
 .agent-menu-sep {
   height: 1px;
   background: var(--surface2);

frontend/packages/dashboard/src/tabs.js

@@ -328,8 +328,8 @@ window.marked = marked;
   // ─── per-agent context menu ──────────────────────────────────────────
   // Three-dot (⋮) button on each agent card for quick single-agent
   // lifecycle actions without needing to select first. State-aware:
-  // restart/stop disabled when agent is stopped, start disabled when
-  // running, destroy/purge hidden for the manager.
+  // restart/stop only shown when running, start only shown when stopped,
+  // destroy/purge hidden for the manager.
   // The button is CSS-invisible until the row is hovered (or menu is
   // open) so it doesn't clutter quiet rows.
 
@@ -351,12 +351,12 @@ window.marked = marked;
   document.addEventListener('click', (e) => {
     if (!e.target.closest('.agent-menu')) closeAllAgentMenus();
   }, true);
-  // Close on Escape (shares the keydown listener below with selection-clear;
-  // close happens first since no selection change is needed here).
+  // Close on Escape. stopImmediatePropagation so the selection-clear
+  // handler on the same element doesn't also fire when a menu is open.
   document.addEventListener('keydown', (e) => {
     if (e.key === 'Escape' && openAgentMenu) {
       closeAllAgentMenus();
-      e.stopPropagation();
+      e.stopImmediatePropagation();
     }
   }, true);
 
@@ -401,16 +401,11 @@ window.marked = marked;
         class: 'agent-menu-item',
         role: 'menuitem',
       }, label);
-      if (opts.disabled) {
-        item.disabled = true;
-        if (opts.title) item.title = opts.title;
-      } else {
-        item.addEventListener('click', async () => {
-          closeAllAgentMenus();
-          if (opts.confirm && !confirm(opts.confirm)) return;
-          await agentMenuPost(opts.action, c.name, opts.body || null);
-        });
-      }
+      item.addEventListener('click', async () => {
+        closeAllAgentMenus();
+        if (opts.confirm && !confirm(opts.confirm)) return;
+        await agentMenuPost(opts.action, c.name, opts.body || null);
+      });
       li.append(item);
       return li;
     }
@@ -419,29 +414,19 @@ window.marked = marked;
       return el('li', { class: 'agent-menu-sep', role: 'separator' });
     }
 
+    // Show only actions that are applicable in the current state.
+    if (c.running) {
+      dropdown.append(
+        menuItem('↺ R3ST4RT', { action: '/restart/', confirm: `restart ${c.name}?` }),
+        menuItem('■ ST0P', { action: '/kill/', confirm: `stop ${c.name}?` }),
+      );
+    } else {
+      dropdown.append(
+        menuItem('▶ ST4RT', { action: '/start/', confirm: `start ${c.name}?` }),
+      );
+    }
     dropdown.append(
-      menuItem('↺ R3ST4RT', {
-        action: '/restart/',
-        disabled: !c.running,
-        title: 'agent is stopped',
-        confirm: `restart ${c.name}?`,
-      }),
-      menuItem('■ ST0P', {
-        action: '/kill/',
-        disabled: !c.running,
-        title: 'agent is already stopped',
-        confirm: `stop ${c.name}?`,
-      }),
-      menuItem('▶ ST4RT', {
-        action: '/start/',
-        disabled: c.running,
-        title: 'agent is already running',
-        confirm: `start ${c.name}?`,
-      }),
-      menuItem('↻ R3BU1LD', {
-        action: '/rebuild/',
-        confirm: `rebuild ${c.name}? hot-reloads the container.`,
-      }),
+      menuItem('↻ R3BU1LD', { action: '/rebuild/', confirm: `rebuild ${c.name}? hot-reloads the container.` }),
     );
 
     if (!c.is_manager) {