Function deep_merge

atomic-agent/src/hooks/manifest.rs:355–364

Deep-merge `extra` into `root`: objects merge recursively, arrays union by value (no duplicates), scalars overwrite. Used for non-hook settings such as Claude's `permissions.deny` rule.

(root: &mut Map<String, Value>, extra: &Map<String, Value>)

/// value (no duplicates), scalars overwrite. Used for non-hook settings such
/// as Claude's `permissions.deny` rule.
fn deep_merge(root: &mut Map<String, Value>, extra: &Map<String, Value>) {
    for (key, value) in extra {
        match root.get_mut(key) {
            Some(existing) => merge_value(existing, value),
            None => {
                root.insert(key.clone(), value.clone());
            }
        }
    }
}

fn merge_value(target: &mut Value, source: &Value) {
    match (target, source) {