Add user information and calendar list to sidebar

Backend changes:
- Add /api/user/info endpoint to fetch user details and calendar list
- Create UserInfo and CalendarInfo models for API responses
- Filter out generic calendar collections from sidebar display
- Extract readable calendar names with proper title case formatting

Frontend changes:
- Fetch and display user info (username, server URL) in sidebar header
- Show list of user's calendars with hover effects and styling
- Add loading states and error handling for user info
- Reorganize sidebar layout: header, navigation, calendar list, logout

Styling:
- Enhanced sidebar with user info section and calendar list
- Responsive design hides user info and calendar list on mobile
- Improved logout button positioning in sidebar footer
- Professional styling with proper spacing and visual hierarchy

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

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

src/app.rs

@@ -2,7 +2,7 @@ use yew::prelude::*;
 use yew_router::prelude::*;
 use gloo_storage::{LocalStorage, Storage};
 use crate::components::{Login, Calendar};
-use crate::services::{CalendarService, CalendarEvent};
+use crate::services::{CalendarService, CalendarEvent, UserInfo, CalendarInfo};
 use std::collections::HashMap;
 use chrono::{Local, NaiveDate, Datelike};
 
@@ -21,6 +21,8 @@ pub fn App() -> Html {
     let auth_token = use_state(|| -> Option<String> {
         LocalStorage::get("auth_token").ok()
     });
+    
+    let user_info = use_state(|| -> Option<UserInfo> { None });
 
     let on_login = {
         let auth_token = auth_token.clone();
@@ -31,12 +33,57 @@ pub fn App() -> Html {
 
     let on_logout = {
         let auth_token = auth_token.clone();
+        let user_info = user_info.clone();
         Callback::from(move |_| {
             let _ = LocalStorage::delete("auth_token");
             auth_token.set(None);
+            user_info.set(None);
         })
     };
 
+    // Fetch user info when token is available
+    {
+        let user_info = user_info.clone();
+        let auth_token = auth_token.clone();
+        
+        use_effect_with((*auth_token).clone(), move |token| {
+            if let Some(token) = token {
+                let user_info = user_info.clone();
+                let token = token.clone();
+                
+                wasm_bindgen_futures::spawn_local(async move {
+                    let calendar_service = CalendarService::new();
+                    
+                    // Get password from stored credentials
+                    let password = if let Ok(credentials_str) = LocalStorage::get::<String>("caldav_credentials") {
+                        if let Ok(credentials) = serde_json::from_str::<serde_json::Value>(&credentials_str) {
+                            credentials["password"].as_str().unwrap_or("").to_string()
+                        } else {
+                            String::new()
+                        }
+                    } else {
+                        String::new()
+                    };
+                    
+                    if !password.is_empty() {
+                        match calendar_service.fetch_user_info(&token, &password).await {
+                            Ok(info) => {
+                                user_info.set(Some(info));
+                            }
+                            Err(err) => {
+                                web_sys::console::log_1(&format!("Failed to fetch user info: {}", err).into());
+                            }
+                        }
+                    }
+                });
+            } else {
+                user_info.set(None);
+            }
+            
+            || ()
+        });
+    }
+
     html! {
         <BrowserRouter>
             <div class="app">
@@ -47,11 +94,51 @@ pub fn App() -> Html {
                                 <aside class="app-sidebar">
                                     <div class="sidebar-header">
                                         <h1>{"Calendar App"}</h1>
+                                        {
+                                            if let Some(ref info) = *user_info {
+                                                html! {
+                                                    <div class="user-info">
+                                                        <div class="username">{&info.username}</div>
+                                                        <div class="server-url">{&info.server_url}</div>
+                                                    </div>
+                                                }
+                                            } else {
+                                                html! { <div class="user-info loading">{"Loading..."}</div> }
+                                            }
+                                        }
                                     </div>
                                     <nav class="sidebar-nav">
                                         <Link<Route> to={Route::Calendar} classes="nav-link">{"Calendar"}</Link<Route>>
-                                        <button onclick={on_logout} class="logout-button">{"Logout"}</button>
                                     </nav>
+                                    {
+                                        if let Some(ref info) = *user_info {
+                                            if !info.calendars.is_empty() {
+                                                html! {
+                                                    <div class="calendar-list">
+                                                        <h3>{"My Calendars"}</h3>
+                                                        <ul>
+                                                            {
+                                                                info.calendars.iter().map(|cal| {
+                                                                    html! {
+                                                                        <li key={cal.path.clone()}>
+                                                                            <span class="calendar-name">{&cal.display_name}</span>
+                                                                        </li>
+                                                                    }
+                                                                }).collect::<Html>()
+                                                            }
+                                                        </ul>
+                                                    </div>
+                                                }
+                                            } else {
+                                                html! { <div class="no-calendars">{"No calendars found"}</div> }
+                                            }
+                                        } else {
+                                            html! {}
+                                        }
+                                    }
+                                    <div class="sidebar-footer">
+                                        <button onclick={on_logout} class="logout-button">{"Logout"}</button>
+                                    </div>
                                 </aside>
                                 <main class="app-main">
                                     <Switch<Route> render={move |route| {