v0.4.23

[0.4.23]

Added

• new_revenue_event() and new_revenue_event_async() for tracking revenue with Umami's new revenue feature
• Revenue events automatically inject revenue (float) and currency (ISO 4217 string) into event custom data
• Input validation: revenue must be a number >= 0, currency must be a non-empty string
• Defaults to event_name='revenue' and currency='USD' for simple usage
• 15 new tests covering sync/async revenue events, validation, and edge cases