Fix ArgumentError when Rails.logger is wrapped by SemanticLogger

[kdonovan]

When OS (or any app) wraps Rails.logger with SemanticLogger, logger.level returns a symbol (e.g. :info, :debug) instead of the standard Ruby Logger integer constants. The override-warning logic in DeclarativeInitialization::Internal#warn_override? was doing logger.level <= Logger::DEBUG, which raised ArgumentError: comparison of Symbol with 0 failed in production.

Change: Only compare logger.level to Logger::DEBUG when level is an integer. If the logger uses a non-integer level (e.g. SemanticLogger), skip the level check and do not warn—so behavior in Rails dev/test is unchanged, standard Logger behavior is unchanged, and SemanticLogger (and similar) no longer raise.

Bump to 0.2.1 with changelog entry.