feat: implement local-files feature with various enhancements and cleanup

k-tv-backend/api/src/error.rs

@@ -36,6 +36,7 @@ pub enum ApiError {
     #[error("auth_required")]
     AuthRequired,
 
+    #[allow(dead_code)]
     #[error("Not found: {0}")]
     NotFound(String),
 
@@ -165,10 +166,12 @@ impl ApiError {
         Self::Validation(msg.into())
     }
 
+    #[cfg(feature = "local-files")]
     pub fn internal(msg: impl Into<String>) -> Self {
         Self::Internal(msg.into())
     }
 
+    #[cfg(feature = "local-files")]
     pub fn not_found(msg: impl Into<String>) -> Self {
         Self::NotFound(msg.into())
     }
@@ -178,5 +181,3 @@ impl ApiError {
     }
 }
 
-/// Result type alias for API handlers
-pub type ApiResult<T> = Result<T, ApiError>;