[refactor] improve code readability, streamline initialization, update error handling, and format multi-line statements for consistency

crates/polyscribe-core/src/config.rs

@@ -9,7 +9,7 @@ const ENV_PREFIX: &str = "POLYSCRIBE";
 ///
 /// Contains paths to models and plugins directories that can be customized
 /// through configuration files or environment variables.
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
 pub struct Config {
     /// Directory path where ML models are stored
     pub models_dir: Option<PathBuf>,
@@ -17,14 +17,7 @@ pub struct Config {
     pub plugins_dir: Option<PathBuf>,
 }
 
-impl Default for Config {
-    fn default() -> Self {
-        Self {
-            models_dir: None,
-            plugins_dir: None,
-        }
-    }
-}
+// Default is derived
 
 /// Service for managing Polyscribe configuration
 ///
@@ -36,7 +29,7 @@ impl ConfigService {
     /// Loads configuration from disk or returns default values if not found
     ///
     /// This function attempts to read the configuration file from disk. If the file
-    /// doesn't exist or can't be parsed, it falls back to default values. 
+    /// doesn't exist or can't be parsed, it falls back to default values.
     /// Environment variable overrides are then applied to the configuration.
     pub fn load_or_default() -> Result<Config> {
         let mut cfg = Self::read_disk().unwrap_or_default();