Add holiday promotion, snowflakes effect, and Spotify music widget

- Added holiday promotion banner with 2026WITHMARINARA discount code
- Added dismiss functionality for promotion with persistent state
- Implemented snowflakes animation effect with toggle
- Added Spotify music widget above chat input
- Widget matches extension theme colors and positioning
- Added Display Options toggles to show/hide feature toggles
- Improved responsive design and mobile support

src/systems/ui/theme.js

@@ -76,6 +76,27 @@ export function toggleAnimations() {
     }
 }
 
+/**
+ * Updates visibility of feature toggles in main panel based on settings
+ */
+export function updateFeatureTogglesVisibility() {
+    const $featuresRow = $('#rpg-features-row');
+    const $htmlToggle = $('#rpg-html-toggle-wrapper');
+    const $spotifyToggle = $('#rpg-spotify-toggle-wrapper');
+    const $snowflakesToggle = $('#rpg-snowflakes-toggle-wrapper');
+
+    // Show/hide individual toggles
+    $htmlToggle.toggle(extensionSettings.showHtmlToggle);
+    $spotifyToggle.toggle(extensionSettings.showSpotifyToggle);
+    $snowflakesToggle.toggle(extensionSettings.showSnowflakesToggle);
+
+    // Hide entire row if all toggles are hidden
+    const anyVisible = extensionSettings.showHtmlToggle ||
+                      extensionSettings.showSpotifyToggle ||
+                      extensionSettings.showSnowflakesToggle;
+    $featuresRow.toggle(anyVisible);
+}
+
 /**
  * Updates the settings popup theme in real-time.
  * Backwards compatible wrapper for SettingsModal class.