feat: add OutputFormat enum and remove unused imports

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

src/modes/common.rs

@@ -1,4 +1,3 @@
-use crate::Args;
 use crate::config;
 use crate::compression_engine::CompressionType;
 use crate::meta_plugin::MetaPluginType;
@@ -13,6 +12,14 @@ use std::str::FromStr;
 use strum::IntoEnumIterator;
 use serde::{Deserialize, Serialize};
 
+#[derive(Debug, Clone, strum::EnumString, strum::Display)]
+#[strum(ascii_case_insensitive)]
+pub enum OutputFormat {
+    Table,
+    Json,
+    Yaml,
+}
+
 pub fn get_meta_from_env() -> HashMap<String, String> {
     debug!("COMMON: Getting meta from KEEP_META_*");
     let re = Regex::new(r"^KEEP_META_(.+)$").unwrap();