fix: remove unused KeyValue struct and related fields

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

src/args.rs

@@ -2,7 +2,7 @@ use std::path::PathBuf;
 use std::str::FromStr;
 
 use clap::*;
-use anyhow::{Error, anyhow};
+use anyhow::Error;
 
 /**
  * Main struct for command-line arguments.
@@ -78,14 +78,6 @@ pub struct ModeArgs {
  */
 #[derive(Parser, Debug, Clone)]
 pub struct ItemArgs {
-    #[arg(help_heading("Item Options"), short, long, conflicts_with_all(["get", "delete", "status"]))]
-    #[arg(help(
-        "Set metadata for the item using the format KEY=[VALUE], the metadata will be removed if VALUE is not provided"
-    ))]
-    #[arg(value_parser = clap::value_parser!(KeyValue))]
-    pub meta: Vec<KeyValue>,
-
-
     #[arg(help_heading("Item Options"), short, long, env("KEEP_COMPRESSION"))]
     #[arg(help("Compression algorithm to use when saving items"))]
     pub compression: Option<String>,