minor cleanup with traits

crates/chattyness-error/src/lib.rs

@@ -1,6 +1,27 @@
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
+/// Extension trait for Option to convert to AppError::NotFound.
+///
+/// Reduces boilerplate when fetching entities that may not exist.
+///
+/// # Example
+/// ```rust
+/// use chattyness_error::OptionExt;
+///
+/// let scene = get_scene_by_id(&pool, id).await?.or_not_found("Scene")?;
+/// ```
+pub trait OptionExt<T> {
+    /// Convert None to AppError::NotFound with a descriptive message.
+    fn or_not_found(self, entity: &str) -> Result<T, AppError>;
+}
+
+impl<T> OptionExt<T> for Option<T> {
+    fn or_not_found(self, entity: &str) -> Result<T, AppError> {
+        self.ok_or_else(|| AppError::NotFound(format!("{} not found", entity)))
+    }
+}
+
 /// Application error types for chattyness.
 ///
 /// All errors derive From for automatic conversion where applicable.