feat: Improve stability of file search discovery in background (#431)

* feat: Improve scan runtime performance and RSS

* chore: Comprehensive randomized fuzzy mutation testing

It's such a shame that we keep commiting regressions that are leading ot
the missed events from the file watcher. I want to minimize this to 0.

* chore: Update docs for - chore: Comprehensive randomized fuzzy mutation testing

* chore: Update docs for - chore: Update docs for - chore: Comprehensive randomized fuzzy mutation testing

* test: Verbose stress test output

crates/fff-mcp/src/main.rs

@@ -15,7 +15,7 @@ mod update_check;
 use clap::Parser;
 use fff::file_picker::FilePicker;
 use fff::frecency::FrecencyTracker;
-use fff::{FFFMode, SharedFrecency, SharedPicker};
+use fff::{FFFMode, SharedFilePicker, SharedFrecency};
 use git2::Repository;
 use mimalloc::MiMalloc;
 use rmcp::{ServiceExt, transport::stdio};
@@ -232,7 +232,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         }
     };
 
-    let shared_picker = SharedPicker::default();
+    let shared_picker = SharedFilePicker::default();
     let shared_frecency = SharedFrecency::default();
     if let Some(frecency_db_path) = args.frecency_db_path {
         match FrecencyTracker::new(&frecency_db_path, false) {

crates/fff-mcp/src/server.rs

@@ -12,7 +12,7 @@ use crate::cursor::CursorStore;
 use crate::output::{GrepFormatter, OutputMode, file_suffix};
 use fff::grep::{GrepMode, GrepSearchOptions, has_regex_metacharacters};
 use fff::types::{FileItem, PaginationArgs};
-use fff::{FuzzySearchOptions, QueryParser, SharedFrecency, SharedPicker};
+use fff::{FuzzySearchOptions, QueryParser, SharedFilePicker, SharedFrecency};
 use fff_query_parser::AiGrepConfig;
 use rmcp::handler::server::router::tool::ToolRouter;
 use rmcp::handler::server::wrapper::Parameters;
@@ -160,7 +160,7 @@ pub struct MultiGrepParams {
 
 #[derive(Clone)]
 pub struct FffServer {
-    picker: SharedPicker,
+    picker: SharedFilePicker,
     #[allow(dead_code)]
     frecency: SharedFrecency,
     cursor_store: Arc<Mutex<CursorStore>>,
@@ -169,7 +169,7 @@ pub struct FffServer {
 }
 
 impl FffServer {
-    pub fn new(picker: SharedPicker, frecency: SharedFrecency) -> Self {
+    pub fn new(picker: SharedFilePicker, frecency: SharedFrecency) -> Self {
         Self {
             picker,
             frecency,