feat(holiday-system): implement comprehensive holiday management features

- Added holiday types and organization holidays management with CRUD operations.
- Introduced country holidays import functionality using the date-holidays npm package.
- Created database migrations for holiday types and organization holidays tables.
- Developed a holiday calendar component for visual representation and management of holidays.
- Enhanced API routes for holiday-related operations and integrated them into the admin center.
- Updated frontend localization for holiday management features.
- Implemented scripts for populating holidays in the database for 200+ countries.

worklenz-backend/scripts/run-holiday-population.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+echo "🌍 Starting Holiday Population Script..."
+echo "This will populate the database with holidays for 200+ countries using the date-holidays npm package."
+echo ""
+
+# Check if Node.js is installed
+if ! command -v node &> /dev/null; then
+    echo "❌ Node.js is not installed. Please install Node.js first."
+    exit 1
+fi
+
+# Check if the script exists
+if [ ! -f "scripts/populate-holidays.js" ]; then
+    echo "❌ Holiday population script not found."
+    exit 1
+fi
+
+# Run the holiday population script
+echo "🚀 Running holiday population script..."
+node scripts/populate-holidays.js
+
+echo ""
+echo "✅ Holiday population completed!"
+echo "You can now use the holiday import feature in the admin center."