feat(ui): enhance frontend architecture and improve user experience

Refactor the frontend to use a more consistent design system and improve the overall user interface and experience.

- Implement a consistent use of `Card` components across various pages (Dashboard, Settings, Notes, etc.).
- Improve layout responsiveness and spacing in several modules.
- Enhance the Tasks page with drag-and-drop status updates and a Kanban-style view.
- Update the Calendar view with better color coding for task priorities and types.
- Refactor the Bookmarks page to use a grid layout with improved card previews.
- Update the Nginx configuration to handle SPA routing and health checks more effectively.
- Standardize import paths using `@/` aliases.
- Fix minor bugs in message sending and loading states.
- Update Docker configuration to build from source and use a specific backend port.

docker-entrypoint.sh

@@ -6,7 +6,7 @@
 set -e
 
 # Backend configuration
-export BACKEND_PORT=${BACKEND_PORT:-8080}
+export BACKEND_PORT=8081
 export DB_HOST=${DB_HOST:-postgres}
 export DB_PORT=${DB_PORT:-5432}
 export DB_NAME=${DB_NAME:-trackeep}
@@ -23,7 +23,7 @@ echo "Starting Trackeep backend on port ${BACKEND_PORT}..."
 # Wait for backend to be ready
 echo "Waiting for backend to be ready..."
 for i in $(seq 1 30); do
-    if wget --no-verbose --tries=1 --spider http://localhost:${BACKEND_PORT}/health 2>/dev/null; then
+    if wget --no-verbose --tries=1 --spider http://localhost:8081/health 2>/dev/null; then
         echo "Backend is ready!"
         break
     fi
@@ -31,9 +31,6 @@ for i in $(seq 1 30); do
     sleep 2
 done
 
-# Update nginx config to proxy to localhost backend
-sed -i "s|http://trackeep-backend:8080/|http://localhost:${BACKEND_PORT}/|g" /etc/nginx/nginx.conf
-
 # Start nginx
 echo "Starting nginx..."
 nginx -g "daemon off;"