Inconsistent logger usage across utility classes - 6 utility classes missing Logger instances

[sfloess]

Problem

Inconsistent logging configuration across utility classes creates maintenance burden and reduces observability.

Current State

10 total utility classes:

With Logger (4):

• ✅ FileUtil
• ✅ PropertyUtil
• ✅ SoapUtil
• ✅ StringUtil

Without Logger (6):

• ❌ ArrayUtil
• ❌ ClassUtil
• ❌ LoggerUtil (ironically)
• ❌ MethodUtil
• ❌ ObjectUtil
• ❌ UrlUtil

Impact

Observability gaps:

1. ArrayUtil - No logging for validation failures
2. ClassUtil - No logging for reflection errors
3. LoggerUtil - Cannot log its own operations (ironic)
4. MethodUtil - No logging for annotation discovery
5. ObjectUtil - No logging for validation failures
6. UrlUtil - No logging for URL parsing errors

Recommendation

Add loggers to remaining utility classes:

private static final Logger LOGGER = Logger.getLogger(ClassName.class.getName());

Rationale:

• Consistent pattern across all utilities
• Enables debug-level tracing in production
• Helps diagnose framework-level issues
• Low overhead when logging disabled

Related

• Issue ObjectUtil missing logger instance (inconsistent with other utility classes) #147: ObjectUtil missing logger (NOTED but may have been resolved)

Priority

Low - Not blocking functionality, but improves maintainability