Implement default for capacity error

Fix #601

Author: sgued

CHANGELOG.md

@@ -10,6 +10,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Minor fixes to module docs.
 - Make MSRV of 1.87.0 explicit.
 
+- Implement `Default` for `CapacityError`
+
 ## [v0.9.1] - 2025-08-19
 
 ### Added

src/lib.rs

@@ -228,7 +228,7 @@ pub mod _export {
 }
 
 /// The error type for fallible [`Vec`] and [`String`] methods.
-#[derive(Debug)]
+#[derive(Debug, Default)]
 #[non_exhaustive]
 pub struct CapacityError;