fix: make unused fields public and remove pub(crate) visibility

Co-authored-by: aider (openai/andrew/openrouter/qwen/qwen3-coder) <aider@aider.chat>

src/args.rs

@@ -174,8 +174,8 @@ impl FromStr for NumberOrString {
  */
 #[derive(Debug, Clone)]
 pub struct KeyValue {
-    pub(crate) key: String,
-    pub(crate) value: String,
+    pub key: String,
+    pub value: String,
 }
 
 impl FromStr for KeyValue {