Clean up debug logging and fix compiler warnings

- Remove non-critical debug logs from backend CalDAV parsing
- Remove all-day event debug logs from frontend components
- Fix unused variable warnings with underscore prefixes
- Keep essential logging while reducing noise

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

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

backend/src/handlers/ics_fetcher.rs

@@ -491,26 +491,18 @@ fn deduplicate_events(mut events: Vec<VEvent>) -> Vec<VEvent> {
     let mut uid_groups: HashMap<String, Vec<VEvent>> = HashMap::new();
     
     for event in events.drain(..) {
-        // Debug logging to understand what's happening
-        println!("🔍 Event: '{}' at {} (RRULE: {}) - UID: {}", 
-            event.summary.as_ref().unwrap_or(&"No Title".to_string()),
-            event.dtstart.format("%Y-%m-%d %H:%M"),
-            if event.rrule.is_some() { "Yes" } else { "No" },
-            event.uid
-        );
         
         uid_groups.entry(event.uid.clone()).or_insert_with(Vec::new).push(event);
     }
     
     let mut uid_deduplicated_events = Vec::new();
     
-    for (uid, mut events_with_uid) in uid_groups.drain() {
+    for (_uid, mut events_with_uid) in uid_groups.drain() {
         if events_with_uid.len() == 1 {
             // Only one event with this UID, keep it
             uid_deduplicated_events.push(events_with_uid.into_iter().next().unwrap());
         } else {
             // Multiple events with same UID - prefer recurring over non-recurring
-            println!("🔍 Found {} events with UID '{}'", events_with_uid.len(), uid);
             
             // Sort by preference: recurring events first, then by completeness
             events_with_uid.sort_by(|a, b| {
@@ -529,10 +521,6 @@ fn deduplicate_events(mut events: Vec<VEvent>) -> Vec<VEvent> {
             
             // Keep the first (preferred) event
             let preferred_event = events_with_uid.into_iter().next().unwrap();
-            println!("🔄 UID dedup: Keeping '{}' (RRULE: {})",
-                preferred_event.summary.as_ref().unwrap_or(&"No Title".to_string()),
-                if preferred_event.rrule.is_some() { "Yes" } else { "No" }
-            );
             uid_deduplicated_events.push(preferred_event);
         }
     }