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>

frontend/src/components/sidebar.rs

@@ -1,8 +1,8 @@
+use crate::components::CalendarListItem;
+use crate::services::calendar_service::UserInfo;
+use web_sys::HtmlSelectElement;
 use yew::prelude::*;
 use yew_router::prelude::*;
-use web_sys::HtmlSelectElement;
-use crate::services::calendar_service::UserInfo;
-use crate::components::CalendarListItem;
 
 #[derive(Clone, Routable, PartialEq)]
 pub enum Route {
@@ -33,12 +33,11 @@ pub enum Theme {
 }
 
 impl Theme {
-    
     pub fn value(&self) -> &'static str {
         match self {
             Theme::Default => "default",
             Theme::Ocean => "ocean",
-            Theme::Forest => "forest", 
+            Theme::Forest => "forest",
             Theme::Sunset => "sunset",
             Theme::Purple => "purple",
             Theme::Dark => "dark",
@@ -46,7 +45,7 @@ impl Theme {
             Theme::Mint => "mint",
         }
     }
-    
+
     pub fn from_value(value: &str) -> Self {
         match value {
             "ocean" => Theme::Ocean,
@@ -167,14 +166,14 @@ pub fn sidebar(props: &SidebarProps) -> Html {
                 <button onclick={props.on_create_calendar.reform(|_| ())} class="create-calendar-button">
                     {"+ Create Calendar"}
                 </button>
-                
+
                 <div class="view-selector">
                     <select class="view-selector-dropdown" onchange={on_view_change}>
                         <option value="month" selected={matches!(props.current_view, ViewMode::Month)}>{"Month"}</option>
                         <option value="week" selected={matches!(props.current_view, ViewMode::Week)}>{"Week"}</option>
                     </select>
                 </div>
-                
+
                 <div class="theme-selector">
                     <select class="theme-selector-dropdown" onchange={on_theme_change}>
                         <option value="default" selected={matches!(props.current_theme, Theme::Default)}>{"Default"}</option>
@@ -187,9 +186,9 @@ pub fn sidebar(props: &SidebarProps) -> Html {
                         <option value="mint" selected={matches!(props.current_theme, Theme::Mint)}>{"Mint"}</option>
                     </select>
                 </div>
-                
+
                 <button onclick={props.on_logout.reform(|_| ())} class="logout-button">{"Logout"}</button>
             </div>
         </aside>
     }
-}
+}