feat: add booster eligibility role and logging functionality

- Added BOOSTER_ELIGIBILITY_ROLE_ID and LOG_LEVEL to .env.example and README.md
- Updated GitHub Actions workflow to include new environment variables
- Enhanced configuration loading to support booster eligibility role
- Implemented role checking logic in bot handlers and guild member updates
- Introduced logging using Winston for better traceability of actions
- Created tests for guild member update handling to ensure correct role removal
- Refactored DiscordRoleRepository to simplify role position resolution

package.json

@@ -15,7 +15,8 @@
     "@discordjs/builders": "latest",
     "discord.js": "latest",
     "drizzle-orm": "latest",
-    "postgres": "latest"
+    "postgres": "latest",
+    "winston": "^3.19.0"
   },
   "devDependencies": {
     "@types/bun": "^1.3.14",