fix: resolve ownership and borrowing errors and add serde traits

Co-authored-by: aider (openai/andrew/openrouter/google/gemini-2.5-pro) <aider@aider.chat>

src/core/item_service.rs

@@ -8,7 +8,6 @@ use crate::db::{self, Meta};
 use crate::compression_engine::{get_compression_engine, CompressionType};
 use crate::modes::common::settings_compression_type;
 use clap::Command;
-use log::debug;
 use rusqlite::Connection;
 use std::collections::HashMap;
 use std::fs;