feat: comprehensive UI overhaul + budget allocation redesign

Audit & Quality:
- RTL: replaced 121 LTR-only utilities (text-left, pl-, left-) with logical properties
- A11y: focus traps + ARIA on Modal/SlidePanel/TabbedModal, clickable divs→buttons
- Theming: bg-white→bg-surface (170 instances), text-gray→semantic tokens
- Performance: useMemo on filters, loading="lazy" on 24 images
- CSS: prefers-reduced-motion, removed dead animations

Component Splits:
- PostDetailPanel: 1332→623 lines + 4 sub-components
- ArtefactDetailPanel: 972→590 lines + 1 sub-component

Brand Identity — Rawaj (رواج):
- New name, DM Sans font, deep teal palette (#0d9488)
- Custom SVG logo, forest-tinted dark mode
- All emails branded with app name in subject line

Design Refinement:
- Dashboard: merged posts+deadlines into tabbed ActivityFeed, inline stats
- Quieter: removed card lift, brand glow, gradient text, mesh backgrounds
- CampaignDetail: prominent budget card, compact team avatars, Lucide icons
- Consistent page titles via Header.jsx, standardized section headers
- Finance page fully i18n'd (20+ hardcoded strings replaced)

Budget Allocation Redesign:
- Single source of truth: BudgetEntries (Campaign.budget deprecated)
- Validation at all levels: main→campaign→track, expenses blocked if insufficient
- Budget request workflow with CEO approval via public link
- BudgetRequests table, CRUD routes, public approval page
- Budget mutex for race condition prevention
- Idempotent migration for existing campaign budgets

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

client/src/components/PostCard.jsx

@@ -23,11 +23,11 @@ export default function PostCard({ post, onClick, onMove, compact = false, check
     return (
       <div
         onClick={onClick}
-        className="bg-white rounded-lg p-3 border border-border hover:border-brand-primary/30 cursor-pointer transition-all group overflow-hidden card-hover"
+        className="bg-surface rounded-lg p-3 border border-border hover:border-brand-primary/30 cursor-pointer transition-all group overflow-hidden card-hover"
       >
         {post.thumbnail_url && (
           <div className="w-[calc(100%+1.5rem)] h-32 -mx-3 -mt-3 mb-2 rounded-t-lg overflow-hidden">
-            <img src={post.thumbnail_url} alt="" className="w-full h-full object-cover" />
+            <img src={post.thumbnail_url} alt="" className="w-full h-full object-cover" loading="lazy" />
           </div>
         )}