Remove debug logging from RRULE handling

Clean up extensive console logging that was added during RRULE debugging.
Removed debug logs from:
- Frontend RRULE generation in create event modal
- Frontend RRULE parsing in calendar service
- Weekly/monthly/yearly occurrence generation functions
- Backend RRULE processing in events and series handlers

The core functionality remains unchanged - this is purely a cleanup
of temporary debugging output that is no longer needed.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/src/handlers/events.rs

@@ -384,14 +384,9 @@ pub async fn create_event(
         }
     };
 
-    // DEBUG: Log the recurrence field to see what we're receiving
-    println!("🔍 DEBUG: Received recurrence field: '{}'", request.recurrence);
-    println!("🔍 DEBUG: Starts with FREQ=? {}", request.recurrence.starts_with("FREQ="));
-    
     // Check if recurrence is already a full RRULE or just a simple type
     let rrule = if request.recurrence.starts_with("FREQ=") {
         // Frontend sent a complete RRULE string, use it directly
-        println!("🎯 Using complete RRULE from frontend: {}", request.recurrence);
         if request.recurrence.is_empty() {
             None
         } else {
@@ -399,7 +394,6 @@ pub async fn create_event(
         }
     } else {
         // Legacy path: Parse recurrence with BYDAY support for weekly recurrence
-        println!("🔄 Building RRULE from simple recurrence type: {}", request.recurrence);
         match request.recurrence.to_uppercase().as_str() {
             "DAILY" => Some("FREQ=DAILY".to_string()),
             "WEEKLY" => {