feat: Add admin calendar and improve availability management

- Add admin calendar component with booking overview and status management
- Implement treatment-specific availability slots with automatic duration
- Enhance availability management with better UI and error handling
- Move admin credentials to .env configuration
- Add .env.example with all required environment variables
- Update README.md with comprehensive setup guide including PowerShell password hash generation
- Improve slot deletion with proper error handling and user feedback
- Add toast notifications for better UX

.gitignore

@@ -1,49 +1,49 @@
-# Logs
-logs
-*.log
-npm-debug.log*
-yarn-debug.log*
-yarn-error.log*
-pnpm-debug.log*
-lerna-debug.log*
-
-node_modules/
-dist/
-dist-ssr/
-.vite/
-coverage/
-
-# Editor directories and files
-.idea
-.DS_Store
-Thumbs.db
-*.suo
-*.ntvs*
-*.njsproj
-*.sln
-*.sw?
-
-# Turbo
-.turbo
-
-# Storage
-*.local
-.storage/
-
-# Quests
-.quests/
-
-# SQLite
-*.db-journal
-*.db-wal
-*.db-shm
-etilqs_*
-
-# Environment variables
-.env
-.env.*
-!.env.example
-.env.local
-
-# TypeScript cache
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules/
+dist/
+dist-ssr/
+.vite/
+coverage/
+
+# Editor directories and files
+.idea
+.DS_Store
+Thumbs.db
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?
+
+# Turbo
+.turbo
+
+# Storage
+*.local
+.storage/
+
+# Quests
+.quests/
+
+# SQLite
+*.db-journal
+*.db-wal
+*.db-shm
+etilqs_*
+
+# Environment variables
+.env
+.env.*
+!.env.example
+.env.local
+
+# TypeScript cache
 *.tsbuildinfo