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.

src/app/globals.css

@@ -1,8 +1,8 @@
 @import "tailwindcss";
 
 :root {
-  --background: #ffffff;
-  --foreground: #171717;
+  --background: #020617; /* slate-950 */
+  --foreground: #f1f5f9; /* slate-100 */
 }
 
 @theme inline {
@@ -12,15 +12,38 @@
   --font-mono: var(--font-geist-mono);
 }
 
-@media (prefers-color-scheme: dark) {
-  :root {
-    --background: #0a0a0a;
-    --foreground: #ededed;
-  }
-}
-
 body {
   background: var(--background);
   color: var(--foreground);
-  font-family: Arial, Helvetica, sans-serif;
+  font-family: var(--font-geist-mono), 'Courier New', monospace;
+  overflow-x: hidden;
+}
+
+/* Scrollbar tech style */
+::-webkit-scrollbar {
+  width: 8px;
+  height: 8px;
+}
+
+::-webkit-scrollbar-track {
+  background: #1e293b; /* slate-800 */
+}
+
+::-webkit-scrollbar-thumb {
+  background: #475569; /* slate-600 */
+  border-radius: 4px;
+}
+
+::-webkit-scrollbar-thumb:hover {
+  background: #06b6d4; /* cyan-500 */
+}
+
+/* Animations tech */
+@keyframes glow {
+  0%, 100% { box-shadow: 0 0 5px rgba(6, 182, 212, 0.3); }
+  50% { box-shadow: 0 0 20px rgba(6, 182, 212, 0.6); }
+}
+
+.animate-glow {
+  animation: glow 2s ease-in-out infinite;
 }