v1.0.0 of katyayani_core

Katyayani Core SDK — Push notifications (sticky, timer, standard), nudges, event tracking for Flutter apps. Changelog excerpt: - Initial release - Event tracking with batching, persistence, and retry - Push notifications (standard, sticky, timer) - In-app nudges with navigation callbacks - Automatic screen view tracking via KCNavigationObserver - User identity management (identify / reset) - Session management with configurable timeout - Offline event persistence and flush-on-reconnect - enablePushflag for apps that handle push independently