feat(event-notifier): improve notification system initialization safety

- Add READY atomic flag to track full initialization status
- Implement initialize_safe and start_safe methods with mutex protection
- Add wait_until_ready function with configurable timeout
- Create initialize_and_start_with_ready_check helper method
- Replace sleep-based waiting with proper readiness checks
- Add safety checks before sending events
- Replace chrono with std::time for time handling
- Update error handling to provide clear initialization status

This change reduces race conditions in multi-threaded environments
and ensures events are only processed when the system is fully ready.

Cargo.toml

@@ -51,7 +51,7 @@ datafusion = "46.0.0"
 derive_builder = "0.20.2"
 dioxus = { version = "0.6.3", features = ["router"] }
 dirs = "6.0.0"
-dotenv = "0.15.0"
+dotenvy = "0.15.7"
 ecstore = { path = "./ecstore" }
 figment = { version = "0.10.19", features = ["toml", "yaml", "env"] }
 flatbuffers = "25.2.10"