fix: remove unused filter_plugin import and unused ringbuf import

Co-authored-by: aider (openai/andrew/openrouter/deepseek/deepseek-chat-v3.1) <aider@aider.chat>

src/services/item_service.rs

@@ -7,10 +7,8 @@ use crate::services::types::{ItemWithContent, ItemWithMeta};
 use crate::db::{self, Meta};
 use crate::compression_engine::{get_compression_engine, CompressionType};
 use crate::modes::common::settings_compression_type;
-use crate::filter_plugin::FilterChain;
 use clap::Command;
 use log::debug;
-use ringbuf::HeapRb;
 use rusqlite::Connection;
 use std::collections::HashMap;
 use std::fs;
@@ -213,7 +211,6 @@ impl ItemService {
         line_start: Option<usize>,
         line_end: Option<usize>,
         grep: Option<String>,
-        filter: Option<String>,
     ) -> Result<(Box<dyn Read + Send>, String, bool), CoreError> {
         let item_with_meta = self.get_item(conn, id)?;
         let item_id = item_with_meta.item.id.ok_or_else(|| CoreError::InvalidInput("Item missing ID".to_string()))?;