feat: overhaul TODO.md and enhance Kanban components

- Updated TODO.md to reflect the new project structure and phases, marking several tasks as completed.
- Enhanced Kanban components with a tech-inspired design, including new styles for columns and task cards.
- Removed the obsolete reminders service and task processor, streamlining the codebase for better maintainability.
- Introduced a modern API for task management, including CRUD operations and improved error handling.
- Updated global styles for a cohesive dark theme and added custom scrollbar styles.

services/database.ts

@@ -39,7 +39,7 @@ export async function closeDatabaseConnection(): Promise<void> {
 
 // Fonction utilitaire pour les transactions
 export async function withTransaction<T>(
-  callback: (tx: PrismaClient) => Promise<T>
+  callback: (tx: Omit<PrismaClient, '$connect' | '$disconnect' | '$on' | '$transaction' | '$extends'>) => Promise<T>
 ): Promise<T> {
   return await prisma.$transaction(async (tx) => {
     return await callback(tx);