feat: Migrate to hero-models for calendar event data

- Replaced custom `CalendarEvent` model with `heromodels`' `Event` model.
- Updated database interactions and controller logic to use the new model.
- Removed unnecessary `CalendarEvent` model and related code.
- Updated views to reflect changes in event data structure.

actix_mvc_app/src/utils/mod.rs

@@ -7,7 +7,7 @@ use tera::{self, Context, Function, Tera, Value};
 pub mod redis_service;
 
 // Re-export for easier imports
-pub use redis_service::RedisCalendarService;
+// pub use redis_service::RedisCalendarService; // Currently unused
 
 /// Error type for template rendering
 #[derive(Debug)]