🔄 Update Checker

• API Migration: Fully migrated to CraftingStudio Pro API v1 using modern HttpClient.
• API Key Support: Added hardcoded API key support directly in UpdateChecker.java for streamlined authentication.
• Improved Reliability: Replaced legacy HttpURLConnection with asynchronous requests and better error handling.
• Enhanced URLs: Updated download and plugin info links to the new category-based structure.