What's Been Done:
• Fixed NetworkManager List/Set type casting issue
• Implemented try-with-resources for database connections
• Refactored UUIDFetcher - removed static memory leaks, added async handling
• Optimized CacheManager thread safety
• Added database query limits (LIMIT 500/100)
• Removed empty addCustomCharts method
• Added proper import for List type in NetworkManager
• Fixed connection pool resource leak patterns
• Made UUIDFetcher instance-based with proper shutdown
• Updated PlayerUtils to use new UUIDFetcher instance
• Fixed CacheManager getUUID to return CompletableFuture