Change config paths to PathBuf instead of String

src/util/config.rs

@@ -1,15 +1,16 @@
 use clap::Parser;
+use std::path::PathBuf;
 
 #[derive(Parser, Clone)]
 #[command(version, about)]
 pub struct Config {
     #[clap(long, env, default_value = "assets/audio")]
     /// The path to store audio files
-    pub audio_path: String,
+    pub audio_path: PathBuf,
 
     #[clap(long, env, default_value = "assets/images")]
     /// The path to store image files (album covers, profile pictures, playlist covers, etc.)
-    pub image_path: String,
+    pub image_path: PathBuf,
 
     #[clap(long, env)]
     /// Whether to disable user signup