feat: revise login screen with logo and smooth transition to splash

- Replace 'Login to Emby' heading with sofarr logo and subtitle
- Subtitle reads 'Login with your Emby credentials'
- Login form fades out smoothly before splash screen appears
- Form labels remain left-aligned within centered login box

public/index.html

@@ -16,7 +16,8 @@
         <!-- Login Form -->
         <div id="login-container" class="login-container" style="display: none;">
             <div class="login-box">
-                <h2>Login to Emby</h2>
+                <img src="images/sofarr-flashscreen.png" alt="sofarr" class="login-logo">
+                <p class="login-subtitle">Login with your Emby credentials</p>
                 <form id="login-form">
                     <div class="form-group">
                         <label for="username">Username:</label>