Polish UI components and rework AgentConfigForm

Major AgentConfigForm rework with improved adapter configuration
fields and layout. Refine sidebar, breadcrumbs, and card/tab
components for visual consistency. Clean up page layouts across
Activity, Agents, Approvals, Costs, Dashboard, Goals, Inbox,
Issues, Org, and Projects pages. Minor heartbeat-run CLI fix.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/pages/Costs.tsx

@@ -36,8 +36,6 @@ export function Costs() {
 
   return (
     <div className="space-y-6">
-      <h2 className="text-lg font-semibold">Costs</h2>
-
       {isLoading && <p className="text-sm text-muted-foreground">Loading...</p>}
       {error && <p className="text-sm text-destructive">{error.message}</p>}