feat: add SFX volume control and improve audio feedback

- Implemented separate sound effects volume control in settings.
- Updated backend to handle new `sfx_volume` parameter.
- Enhanced UI to include sound effects volume slider in admin panel.
- Integrated sound effects for various user interactions (clicks, navigation, alerts).
- Added a new global sound engine to manage audio synthesis without external files.
- Updated documentation for Docker deployment and Windows packaging.
- Refactored audio context management to ensure sound effects are available post user interaction.

src/pages/MediaScreen.jsx

@@ -2,6 +2,7 @@ import { useState, useEffect, useRef, useCallback } from 'react';
 import { useNavigate } from 'react-router-dom';
 import * as api from '../utils/api';
 import { getApiBase } from '../config';
+import { Sfx } from '../utils/sounds';
 import { API_BASE } from '../utils/api';
 import { getCurrentWindow } from '@tauri-apps/api/window';
 import { enable, disable } from '@tauri-apps/plugin-autostart';
@@ -323,6 +324,9 @@ export default function MediaScreen() {
   }, [reloadPlaylist]);
 
   const applySettings = useCallback((msg) => {
+    if (msg.sfx_volume !== undefined) {
+      Sfx.setVolume(msg.sfx_volume);
+    }
     if (msg.volume !== undefined) {
       const vol = msg.volume / 100;
       setVolume(vol);