Add comprehensive social media management system and improve admin pages

## Social Media Management System
- Add SocialMediaLink database model with platform, URL, icon, and ordering
- Create complete CRUD API endpoints for admin social media management
- Implement admin social media management page with Material-UI DataGrid
- Add "Social Media" menu item to admin navigation
- Update footer to dynamically load and display enabled social media links
- Support multiple platforms: Facebook, Twitter, Instagram, YouTube, LinkedIn, GitHub, TikTok
- Include proper icon mapping and fallback handling

## Admin Pages Improvements
- Replace broken TinyMCE editor with working WYSIWYG rich text editor
- Create SimpleRichEditor component with toolbar for formatting
- Fix admin authentication to use cookies instead of localStorage tokens
- Update all admin API calls to use credentials: 'include'
- Increase content editor height to 800px for better editing experience
- Add Lexical editor component as alternative (not currently used)

## Footer Pages System
- Create 8 comprehensive footer pages: About, Blog, Support, API Docs, Terms, Privacy, Cookies, GDPR
- Implement dynamic footer link management with smart categorization
- Separate Quick Links and Legal sections with automatic filtering
- Remove duplicate hardcoded links and use database-driven system
- All footer pages are fully written with professional content

## Database & Dependencies
- Add uuid package for ID generation
- Update Prisma schema with new SocialMediaLink model and relations
- Seed default social media links for Facebook, Twitter, Instagram, YouTube
- Add Lexical rich text editor packages (@lexical/react, etc.)

## Technical Improvements
- Fix async params compatibility for Next.js 15
- Update MUI DataGrid deprecated props
- Improve admin layout navigation structure
- Add proper TypeScript interfaces for all new components
- Implement proper error handling and user feedback

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

prisma/schema.prisma

@@ -32,6 +32,8 @@ model User {
   createdPages    Page[] @relation("PageCreator")
   updatedPages    Page[] @relation("PageUpdater")
   uploadedFiles   MediaFile[]
+  createdSocialMedia SocialMediaLink[] @relation("SocialMediaCreator")
+  updatedSocialMedia SocialMediaLink[] @relation("SocialMediaUpdater")
 
   @@index([role])
 }
@@ -347,4 +349,24 @@ enum PageStatus {
   DRAFT
   PUBLISHED
   ARCHIVED
+}
+
+model SocialMediaLink {
+  id          String   @id @default(uuid())
+  platform    String   // facebook, twitter, instagram, youtube, linkedin, tiktok, etc.
+  name        String   // Display name (e.g., "Facebook", "Instagram")
+  url         String   // Full URL to the social media profile
+  icon        String   // Icon identifier (material-ui icon name)
+  isEnabled   Boolean  @default(true)
+  order       Int      @default(0) // Display order in footer
+  createdBy   String
+  updatedBy   String
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+
+  creator     User     @relation("SocialMediaCreator", fields: [createdBy], references: [id])
+  updater     User     @relation("SocialMediaUpdater", fields: [updatedBy], references: [id])
+
+  @@unique([platform])
+  @@index([isEnabled, order])
 }