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/EmptyState.jsx

@@ -21,7 +21,7 @@ export default function EmptyState({
         {actionLabel && (
           <button
             onClick={onAction}
-            className="mt-3 text-sm text-brand-primary hover:text-brand-primary-light font-medium"
+            className="mt-3 text-sm text-brand-primary hover:text-brand-primary-light font-medium transition-colors"
           >
             {actionLabel}
           </button>
@@ -44,7 +44,7 @@ export default function EmptyState({
         {actionLabel && (
           <button
             onClick={onAction}
-            className="px-5 py-2.5 bg-brand-primary text-white rounded-lg text-sm font-medium hover:bg-brand-primary-light shadow-sm transition-all hover:-translate-y-0.5"
+            className="px-5 py-2.5 bg-brand-primary text-white rounded-lg text-sm font-medium hover:bg-brand-primary-light transition-colors"
           >
             {actionLabel}
           </button>
@@ -52,7 +52,7 @@ export default function EmptyState({
         {secondaryActionLabel && (
           <button
             onClick={onSecondaryAction}
-            className="px-5 py-2.5 bg-white border border-border text-text-primary rounded-lg text-sm font-medium hover:bg-surface-secondary transition-colors"
+            className="px-5 py-2.5 bg-surface border border-border text-text-primary rounded-lg text-sm font-medium hover:bg-surface-secondary transition-colors"
           >
             {secondaryActionLabel}
           </button>