fix: preserve cockpit steps across view toggles and show full step info

Backend: stop wiping pending_task_lane when AI response has no new
[ACTIONS]/[QUESTIONS] markers — previous task lane state is still
relevant until replaced by new markers.

Frontend (selectChat): don't eagerly clear task lane before server
response arrives; restore from sessionStorage as fallback when
pending_task_lane is null (covers sessions before backend fix).

StepsPanel: show description and command for all steps instead of
hiding behind hover/active-only visibility. Commands render as
inline code blocks.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/assistant/StepsPanel.tsx

@@ -101,15 +101,22 @@ export function StepsPanel({
                   'transition-colors duration-200',
                   isCompleted && 'line-through opacity-70',
                 )}>{action.label}</span>
-                {/* Show description for active step and on hover for others */}
                 {action.description && (
                   <p className={cn(
-                    'text-xs text-muted-foreground mt-0.5 leading-relaxed transition-all duration-200',
-                    isActive ? 'opacity-100 max-h-20' : 'opacity-0 max-h-0 group-hover:opacity-70 group-hover:max-h-20 overflow-hidden',
+                    'text-xs text-muted-foreground mt-0.5 leading-relaxed',
+                    isCompleted && 'opacity-60',
                   )}>
                     {action.description}
                   </p>
                 )}
+                {action.command && (
+                  <code className={cn(
+                    'block text-[11px] font-mono mt-1 px-2 py-1 rounded bg-white/[0.04] border border-white/[0.06] text-muted-foreground break-all',
+                    isCompleted && 'opacity-60',
+                  )}>
+                    {action.command}
+                  </code>
+                )}
               </div>
 
               {/* Active indicator */}