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/auth.rs

@@ -2,16 +2,16 @@ use chrono::{Duration, Utc};
 use jsonwebtoken::{decode, encode, Algorithm, DecodingKey, EncodingKey, Header, Validation};
 use serde::{Deserialize, Serialize};
 
-use crate::models::{CalDAVLoginRequest, AuthResponse, ApiError};
-use crate::config::CalDAVConfig;
 use crate::calendar::CalDAVClient;
+use crate::config::CalDAVConfig;
+use crate::models::{ApiError, AuthResponse, CalDAVLoginRequest};
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct Claims {
     pub username: String,
     pub server_url: String,
-    pub exp: i64,     // Expiration time
-    pub iat: i64,     // Issued at
+    pub exp: i64, // Expiration time
+    pub iat: i64, // Issued at
 }
 
 #[derive(Clone)]
@@ -33,22 +33,25 @@ impl AuthService {
         // Create CalDAV config with provided credentials
         let caldav_config = CalDAVConfig::new(
             request.server_url.clone(),
-            request.username.clone(), 
-            request.password.clone()
+            request.username.clone(),
+            request.password.clone(),
         );
         println!("📝 Created CalDAV config");
 
         // Test authentication against CalDAV server
         let caldav_client = CalDAVClient::new(caldav_config.clone());
         println!("🔗 Created CalDAV client, attempting to discover calendars...");
-        
+
         // Try to discover calendars as an authentication test
         match caldav_client.discover_calendars().await {
             Ok(calendars) => {
-                println!("✅ Authentication successful! Found {} calendars", calendars.len());
+                println!(
+                    "✅ Authentication successful! Found {} calendars",
+                    calendars.len()
+                );
                 // Authentication successful, generate JWT token
                 let token = self.generate_token(&request.username, &request.server_url)?;
-                
+
                 Ok(AuthResponse {
                     token,
                     username: request.username,
@@ -58,7 +61,9 @@ impl AuthService {
             Err(err) => {
                 println!("❌ Authentication failed: {:?}", err);
                 // Authentication failed
-                Err(ApiError::Unauthorized("Invalid CalDAV credentials or server unavailable".to_string()))
+                Err(ApiError::Unauthorized(
+                    "Invalid CalDAV credentials or server unavailable".to_string(),
+                ))
             }
         }
     }
@@ -69,13 +74,17 @@ impl AuthService {
     }
 
     /// Create CalDAV config from token
-    pub fn caldav_config_from_token(&self, token: &str, password: &str) -> Result<CalDAVConfig, ApiError> {
+    pub fn caldav_config_from_token(
+        &self,
+        token: &str,
+        password: &str,
+    ) -> Result<CalDAVConfig, ApiError> {
         let claims = self.verify_token(token)?;
-        
+
         Ok(CalDAVConfig::new(
             claims.server_url,
-            claims.username, 
-            password.to_string()
+            claims.username,
+            password.to_string(),
         ))
     }
 
@@ -93,8 +102,11 @@ impl AuthService {
         }
 
         // Basic URL validation
-        if !request.server_url.starts_with("http://") && !request.server_url.starts_with("https://") {
-            return Err(ApiError::BadRequest("Server URL must start with http:// or https://".to_string()));
+        if !request.server_url.starts_with("http://") && !request.server_url.starts_with("https://")
+        {
+            return Err(ApiError::BadRequest(
+                "Server URL must start with http:// or https://".to_string(),
+            ));
         }
 
         Ok(())
@@ -131,4 +143,4 @@ impl AuthService {
 
         Ok(token_data.claims)
     }
-}
+}