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/CampaignCalendar.jsx

@@ -41,7 +41,7 @@ export default function CampaignCalendar({ campaigns = [] }) {
   }
 
   return (
-    <div className="bg-white rounded-xl border border-border overflow-hidden">
+    <div className="bg-surface rounded-xl border border-border overflow-hidden">
       {/* Header */}
       <div className="flex items-center justify-between px-6 py-4 border-b border-border">
         <h3 className="text-lg font-semibold text-text-primary">
@@ -109,8 +109,8 @@ export default function CampaignCalendar({ campaigns = [] }) {
                     <div
                       key={campaign._id || ci}
                       className={`h-5 text-[10px] font-medium text-white flex items-center px-1 truncate ${CAMPAIGN_COLORS[colorIndex]} ${
-                        isStart ? 'rounded-l-full ml-0' : '-ml-1'
-                      } ${isEnd ? 'rounded-r-full mr-0' : '-mr-1'}`}
+                        isStart ? 'rounded-l-full ms-0' : '-ms-1'
+                      } ${isEnd ? 'rounded-r-full me-0' : '-me-1'}`}
                       title={campaign.name}
                     >
                       {isStart ? campaign.name : ''}