RAM-only event queue — zero device storage for analytics

chore: dart format

v2.1.0 - Simplified 4-Field API

Breaking Changes:
- Removed 'screen' parameter from track() method
- SDK now sends only 4 fields: event_name, timestamp, session_id, platform

What's New:
- Strict 4-field API for maximum privacy
- All deprecated fields removed
- Comprehensive test coverage (26 unit tests + 7 integration tests)

Migration:
- Remove any 'screen:' parameter from track() calls

v2.0.0 - Session-based analytics for GDPR/ePrivacy compliance

Initial release v1.0.0 - Flutter SDK for Respectlytics

v1.0.1 - Standardized privacy documentation