improve error formatting

- Added missing comma in error message for set-cell command.
- Reformatted error messages for consistency.
- Minor formatting changes to improve readability.

Co-Authored-By: fiddlerwoaroof/git-smart-commit (gpt-oss:20b)

src/command/parse.rs

@@ -122,7 +122,7 @@ fn parse_command(segment: &str) -> Result<Command, String> {
         "set-cell" => {
             if args.len() < 2 {
                 return Err(
-                    "set-cell requires a value and at least one Cat/Item coordinate".to_string()
+                    "set-cell requires a value and at least one Cat/Item coordinate".to_string(),
                 );
             }
             let value = parse_cell_value(&args[0])?;
@@ -254,7 +254,10 @@ fn parse_command(segment: &str) -> Result<Command, String> {
 
 fn require_args(word: &str, args: &[String], n: usize) -> Result<(), String> {
     if args.len() < n {
-        Err(format!("{word} requires {n} argument(s), got {}", args.len()))
+        Err(format!(
+            "{word} requires {n} argument(s), got {}",
+            args.len()
+        ))
     } else {
         Ok(())
     }
@@ -287,7 +290,9 @@ fn parse_axis(s: &str) -> Result<Axis, String> {
         "column" | "col" => Ok(Axis::Column),
         "page" => Ok(Axis::Page),
         "none" => Ok(Axis::None),
-        _ => Err(format!("Unknown axis: {s} (expected row, column, page, none)")),
+        _ => Err(format!(
+            "Unknown axis: {s} (expected row, column, page, none)"
+        )),
     }
 }