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/CampaignDetailPanel.jsx

@@ -130,7 +130,7 @@ export default function CampaignDetailPanel({ campaign, onClose, onSave, onDelet
                 form.status === 'paused' ? 'bg-amber-100 text-amber-700' :
                 form.status === 'completed' ? 'bg-blue-100 text-blue-700' :
                 form.status === 'cancelled' ? 'bg-red-100 text-red-700' :
-                'bg-gray-100 text-gray-600'
+                'bg-gray-100 text-text-secondary'
               }`}>
                 {statusOptions.find(s => s.value === form.status)?.label}
               </span>
@@ -226,7 +226,7 @@ export default function CampaignDetailPanel({ campaign, onClose, onSave, onDelet
             {/* Platforms */}
             <div>
               <label className="block text-xs font-medium text-text-tertiary mb-1">{t('campaigns.platforms')}</label>
-              <div className="flex flex-wrap gap-2 p-2 border border-border rounded-lg bg-white min-h-[38px]">
+              <div className="flex flex-wrap gap-2 p-2 border border-border rounded-lg bg-surface min-h-[38px]">
                 {Object.entries(PLATFORMS).map(([k, v]) => {
                   const checked = (form.platforms || []).includes(k)
                   return (
@@ -281,7 +281,7 @@ export default function CampaignDetailPanel({ campaign, onClose, onSave, onDelet
               <div>
                 <label className="block text-xs font-medium text-text-tertiary mb-1">
                   {t('campaigns.budget')} ({currencySymbol})
-                  {!permissions?.canSetBudget && <span className="text-[10px] text-text-tertiary ml-1">(Superadmin only)</span>}
+                  {!permissions?.canSetBudget && <span className="text-[10px] text-text-tertiary ms-1">(Superadmin only)</span>}
                 </label>
                 <input
                   type="number"