Fix calendar event fetching to use visible date range

Moved event fetching logic from CalendarView to Calendar component to properly
use the visible date range instead of hardcoded current month. The Calendar
component already tracks the current visible date through navigation, so events
now load correctly for August and other months when navigating.

Changes:
- Calendar component now manages its own events state and fetching
- Event fetching responds to current_date changes from navigation
- CalendarView simplified to just render Calendar component
- Fixed cargo fmt/clippy formatting across codebase

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

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

backend/src/handlers/calendar.rs

@@ -1,12 +1,14 @@
-use axum::{
-    extract::State,
-    http::HeaderMap,
-    response::Json,
-};
+use axum::{extract::State, http::HeaderMap, response::Json};
 use std::sync::Arc;
 
-use crate::{AppState, models::{ApiError, CreateCalendarRequest, CreateCalendarResponse, DeleteCalendarRequest, DeleteCalendarResponse}};
 use crate::calendar::CalDAVClient;
+use crate::{
+    models::{
+        ApiError, CreateCalendarRequest, CreateCalendarResponse, DeleteCalendarRequest,
+        DeleteCalendarResponse,
+    },
+    AppState,
+};
 
 use super::auth::{extract_bearer_token, extract_password_header};
 
@@ -20,22 +22,36 @@ pub async fn create_calendar(
 
     // Validate request
     if request.name.trim().is_empty() {
-        return Err(ApiError::BadRequest("Calendar name is required".to_string()));
+        return Err(ApiError::BadRequest(
+            "Calendar name is required".to_string(),
+        ));
     }
 
     // Create CalDAV config from token and password
-    let config = state.auth_service.caldav_config_from_token(&token, &password)?;
+    let config = state
+        .auth_service
+        .caldav_config_from_token(&token, &password)?;
     let client = CalDAVClient::new(config);
 
     // Create calendar on CalDAV server
-    match client.create_calendar(&request.name, request.description.as_deref(), request.color.as_deref()).await {
+    match client
+        .create_calendar(
+            &request.name,
+            request.description.as_deref(),
+            request.color.as_deref(),
+        )
+        .await
+    {
         Ok(_) => Ok(Json(CreateCalendarResponse {
             success: true,
             message: "Calendar created successfully".to_string(),
         })),
         Err(e) => {
             eprintln!("Failed to create calendar: {}", e);
-            Err(ApiError::Internal(format!("Failed to create calendar: {}", e)))
+            Err(ApiError::Internal(format!(
+                "Failed to create calendar: {}",
+                e
+            )))
         }
     }
 }
@@ -50,11 +66,15 @@ pub async fn delete_calendar(
 
     // Validate request
     if request.path.trim().is_empty() {
-        return Err(ApiError::BadRequest("Calendar path is required".to_string()));
+        return Err(ApiError::BadRequest(
+            "Calendar path is required".to_string(),
+        ));
     }
 
     // Create CalDAV config from token and password
-    let config = state.auth_service.caldav_config_from_token(&token, &password)?;
+    let config = state
+        .auth_service
+        .caldav_config_from_token(&token, &password)?;
     let client = CalDAVClient::new(config);
 
     // Delete calendar on CalDAV server
@@ -65,7 +85,10 @@ pub async fn delete_calendar(
         })),
         Err(e) => {
             eprintln!("Failed to delete calendar: {}", e);
-            Err(ApiError::Internal(format!("Failed to delete calendar: {}", e)))
+            Err(ApiError::Internal(format!(
+                "Failed to delete calendar: {}",
+                e
+            )))
         }
     }
-}
+}