Function merge_value

src/tool_command/args.rs:648–660

Insert `value` into `map` under `key`. If the key is already present and the schema-declared shape is an array, append the new value to a sibling array rather than overwriting — this is how repeated `--keywords foo --keywords bar` accumulates. Called after [`coerce_value`], so the value is already the right JSON type (or a string we'll wrap in an array on first sight of a second occurrence).

(map: &mut Map<String, Value>, key: &str, value: Value)

/// Called after [`coerce_value`], so the value is already the right JSON type
/// (or a string we'll wrap in an array on first sight of a second occurrence).
fn merge_value(map: &mut Map<String, Value>, key: &str, value: Value) {
    if let Some(existing) = map.get_mut(key) {
        match existing {
            Value::Array(arr) => arr.push(value),
            _ => {
                let prev = std::mem::replace(existing, Value::Null);
                *existing = Value::Array(vec![prev, value]);
            }
        }
    } else {
        map.insert(key.to_string(), value);
    }
}

/// Promote any `array<string>` properties from a single string into a real
/// array: split on commas if the user passed `--keywords foo,bar`, or wrap a