v0.2.3

fix: patch bug fixes from code quality scan (0.2.3)

Fixed:
- TMService lock file handle leak with proper context manager
- Duplicate FormatNotSupportedError removed from ol_buses/format_guard
- validate_config() now performs actual validation
- Added missing Any type import to ol_batch/processor
- Moved 8 regex patterns to module-level constants in ol_md/shield
- Removed empty test_ensemble_uses_median_aggregation stub
- Updated test assertions to match actual ModelPool defaults

Changed:
- Version bumped to 0.2.3