feat: Implement Jupiter-style trading interface with token selection

- Add 'You're paying' and 'You're receiving' sections with proper token dropdowns
- Implement balance display and MAX button functionality
- Add automatic receiving amount calculation based on paying amount
- Enhance token selector with icons, names, and balance information
- Improve leverage position value calculations and risk warnings
- Update trade execution to use new paying/receiving token structure
- Maintain all existing functionality including stop loss, take profit, and position management

This creates a more intuitive and professional trading interface that matches Jupiter's UX patterns.

package.json

@@ -7,6 +7,8 @@
     "dev:docker": "next dev --port 3000 --hostname 0.0.0.0",
     "build": "next build",
     "start": "next start",
+    "lint": "next lint",
+    "lint:fix": "next lint --fix",
     "docker:build": "docker compose build",
     "docker:build:optimized": "DOCKER_BUILDKIT=1 COMPOSE_DOCKER_CLI_BUILD=1 COMPOSE_BAKE=true docker compose --progress=plain build --parallel",
     "docker:build:dev": "DOCKER_BUILDKIT=1 COMPOSE_BAKE=true docker compose --progress=plain build --target development",