- Add Metadata field (map[string]string) to Event struct with omitempty
- Add helper methods for common metadata: SetCorrelationID/GetCorrelationID,
SetCausationID/GetCausationID, SetUserID/GetUserID, SetTraceID/GetTraceID,
SetSpanID/GetSpanID
- Add WithMetadataFrom helper for copying metadata between events
- Add metadata key constants for standard fields
- Add comprehensive unit tests for metadata serialization and helpers
- Add store tests verifying metadata persistence
Closes#7
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Test JSON serialization/deserialization, field names, omitempty behavior,
edge cases (empty/nil data, large payloads, special characters including
unicode and control chars), timestamp handling across timezones, nanosecond
precision, version edge cases, and nested data structures.
Closes#1
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
