Fix single event deletion functionality with proper recurring vs non-recurring handling

This commit resolves multiple issues with event deletion:

Backend fixes:
- Fix CalDAV URL construction for DELETE requests (missing slash separator)
- Improve event lookup by href with exact matching and fallback to UID extraction
- Add support for both RFC3339 and simple YYYY-MM-DD date formats in occurrence parsing
- Implement proper logic to distinguish recurring vs non-recurring events in delete_this action
- For non-recurring events: delete entire event from CalDAV server
- For recurring events: add EXDATE to exclude specific occurrences
- Add comprehensive debug logging for troubleshooting deletion issues

Frontend fixes:
- Update callback signatures to support series endpoint parameters (7-parameter tuples)
- Add update_series method to CalendarService for series-specific operations
- Route single occurrence modifications through series endpoint with proper scoping
- Fix all component prop definitions to use new callback signature
- Update all emit calls to pass correct number of parameters

The deletion process now works correctly:
- Single events are completely removed from the calendar
- Recurring event occurrences are properly excluded via EXDATE
- Debug logging helps identify and resolve CalDAV communication issues

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

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

frontend/src/services/calendar_service.rs

@@ -1106,5 +1106,102 @@ impl CalendarService {
         }
     }
 
+    pub async fn update_series(
+        &self,
+        token: &str,
+        password: &str,
+        series_uid: String,
+        title: String,
+        description: String,
+        start_date: String,
+        start_time: String,
+        end_date: String,
+        end_time: String,
+        location: String,
+        all_day: bool,
+        status: String,
+        class: String,
+        priority: Option<u8>,
+        organizer: String,
+        attendees: String,
+        categories: String,
+        reminder: String,
+        recurrence: String,
+        calendar_path: Option<String>,
+        update_scope: String,
+        occurrence_date: Option<String>,
+    ) -> Result<(), String> {
+        let window = web_sys::window().ok_or("No global window exists")?;
+        
+        let opts = RequestInit::new();
+        opts.set_method("POST");
+        opts.set_mode(RequestMode::Cors);
+
+        let body = serde_json::json!({
+            "series_uid": series_uid,
+            "title": title,
+            "description": description,
+            "start_date": start_date,
+            "start_time": start_time,
+            "end_date": end_date,
+            "end_time": end_time,
+            "location": location,
+            "all_day": all_day,
+            "status": status,
+            "class": class,
+            "priority": priority,
+            "organizer": organizer,
+            "attendees": attendees,
+            "categories": categories,
+            "reminder": reminder,
+            "recurrence": recurrence,
+            "recurrence_days": vec![false; 7], // Default - could be enhanced
+            "recurrence_interval": 1_u32, // Default interval
+            "recurrence_end_date": None as Option<String>, // No end date by default
+            "recurrence_count": None as Option<u32>, // No count limit by default
+            "calendar_path": calendar_path,
+            "update_scope": update_scope,
+            "occurrence_date": occurrence_date
+        });
+        
+        let url = format!("{}/calendar/events/series/update", self.base_url);
+
+        let body_string = serde_json::to_string(&body)
+            .map_err(|e| format!("JSON serialization failed: {}", e))?;
+        opts.set_body(&body_string.into());
+        let request = Request::new_with_str_and_init(&url, &opts)
+            .map_err(|e| format!("Request creation failed: {:?}", e))?;
+
+        request.headers().set("Authorization", &format!("Bearer {}", token))
+            .map_err(|e| format!("Authorization header setting failed: {:?}", e))?;
+        
+        request.headers().set("X-CalDAV-Password", password)
+            .map_err(|e| format!("Password header setting failed: {:?}", e))?;
+
+        request.headers().set("Content-Type", "application/json")
+            .map_err(|e| format!("Content-Type header setting failed: {:?}", e))?;
+
+        let resp_value = JsFuture::from(window.fetch_with_request(&request))
+            .await
+            .map_err(|e| format!("Network request failed: {:?}", e))?;
+
+        let resp: Response = resp_value.dyn_into()
+            .map_err(|e| format!("Response cast failed: {:?}", e))?;
+
+        let text = JsFuture::from(resp.text()
+            .map_err(|e| format!("Text extraction failed: {:?}", e))?)
+            .await
+            .map_err(|e| format!("Text promise failed: {:?}", e))?;
+
+        let text_string = text.as_string()
+            .ok_or("Response text is not a string")?;
+
+        if resp.ok() {
+            Ok(())
+        } else {
+            Err(format!("Request failed with status {}: {}", resp.status(), text_string))
+        }
+    }
+
 }