- Replace all hardcoded Tailwind colors with CSS custom properties (--warn, --warn-soft, --text, --muted, --panel-soft, --success, --danger, --muted-strong)
- Use rounded-[10px] instead of rounded-lg for design system consistency
- Add aria-label on dismiss button for accessibility
- Update NeedsAttention label to 'Needs Your Attention' in en.ts and zh.ts
- Create BudgetAlertBanner with threshold detection (>=80% budget utilization)
- Display agent names with percentages, warn color for 80-99%, danger for 100%+
- Dismissible per session with auto-reset on new threshold crossings
- View Costs link navigates to costs section
- Accessible with role=alert, aria-live=assertive, keyboard-dismissible
- Framer Motion fade-in/slide-down animation, respects reduced motion
- Positioned after RecoveryBanner in Dashboard layout