feat: post composition redesign + budget allocation + brand identity (Rawaj)

Post Workflow:
- PostDetail full page (/posts/:id) replaces slide panel approach
- Post = 1 Caption Copy + 1 Body Copy + 1 Design + 0-1 Video
- copy_type field on Translations (caption/body)
- Composition endpoint returns rich data (content preview, languages, thumbnails)
- Stage auto-advances on translation/artefact changes (both link and unlink)
- "Translations" renamed to "Copy" in navigation
- GET /api/posts/:id, /api/translations/:id, /api/artefacts/:id routes added
- PostProduction: "New Post" creates → navigates to full page
- CampaignDetail: click post → navigates to full page
- Inline link picker (no modals) with search + rich item display
- PostComposition sub-components for caption, copy, designs, video, formats, readiness

Budget Allocation:
- Single source of truth: BudgetEntries (Campaign.budget deprecated)
- Budget mutex for race conditions
- Validation at all levels (main → campaign → track, expenses)
- CEO approval workflow: BudgetRequests table, public approval page
- Finance page: request budget UI, budget requests section
- Settings: CEO email field
- All emails branded with "Rawaj —" prefix

Brand Identity:
- Name: Rawaj (رواج) — trending/virality
- Deep teal palette (#0d9488), forest-tinted dark mode
- DM Sans font, custom SVG logo
- Consistent across login, sidebar, emails, public pages

Approval Workflow:
- Single reviewer per artefact (not multi-select)
- Reviewer redirect on public review page
- Server blocks submit-review without reviewer
- Review URLs use APP_URL (not server URL)

UI/UX:
- Scroll clipping fix: Modal, TabbedModal, SlidePanel restructured
  to avoid overflow-y-auto clipping native select dropdowns
- section-card overflow-hidden → overflow-clip
- All page titles via Header.jsx (removed duplicate h1s)
- CampaignDetail redesigned: prominent budget card, compact team

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

client/src/pages/Settings.jsx

@@ -71,7 +71,7 @@ export default function Settings() {
       <p className="text-sm text-text-tertiary">{t('settings.preferences')}</p>
 
       {/* General Settings */}
-      <div className="bg-surface rounded-xl border border-border overflow-hidden">
+      <div className="bg-surface rounded-xl border border-border overflow-clip">
         <div className="px-6 py-4 border-b border-border">
           <h3 className="font-semibold text-text-primary">{t('settings.general')}</h3>
         </div>
@@ -115,7 +115,7 @@ export default function Settings() {
       </div>
 
       {/* Uploads Section */}
-      <div className="bg-surface rounded-xl border border-border overflow-hidden">
+      <div className="bg-surface rounded-xl border border-border overflow-clip">
         <div className="px-6 py-4 border-b border-border">
           <h3 className="font-semibold text-text-primary flex items-center gap-2">
             <Upload className="w-5 h-5 text-brand-primary" />
@@ -153,7 +153,7 @@ export default function Settings() {
       </div>
 
       {/* Tutorial Section */}
-      <div className="bg-surface rounded-xl border border-border overflow-hidden">
+      <div className="bg-surface rounded-xl border border-border overflow-clip">
         <div className="px-6 py-4 border-b border-border">
           <h3 className="font-semibold text-text-primary">{t('settings.onboardingTutorial')}</h3>
         </div>
@@ -188,7 +188,7 @@ export default function Settings() {
 
       {/* Budget Approval (Superadmin only) */}
       {user?.role === 'superadmin' && (
-        <div className="bg-surface rounded-xl border border-border overflow-hidden">
+        <div className="bg-surface rounded-xl border border-border overflow-clip">
           <div className="px-6 py-4 border-b border-border">
             <h3 className="font-semibold text-text-primary flex items-center gap-2">
               <Mail className="w-5 h-5 text-brand-primary" />
@@ -291,7 +291,7 @@ function RolesSection({ roles, loadRoles, t, toast }) {
 
   return (
     <>
-      <div className="bg-surface dark:bg-surface-primary rounded-xl border border-border overflow-hidden">
+      <div className="bg-surface dark:bg-surface-primary rounded-xl border border-border overflow-clip">
         <div className="px-6 py-4 border-b border-border flex items-center justify-between">
           <h3 className="font-semibold text-text-primary flex items-center gap-2">
             <Tag className="w-5 h-5 text-brand-primary" />