feat: persist worker-pause state across restarts

Worker pause states can optionally survive app restarts. A new toggle in
Settings saves the current pause map to settings/worker_pauses.json; on
startup lib.rs restores it before workers are spawned. Backend: new
snapshot/replace helpers in indexer.rs, persist functions in commands.rs
(get/set_worker_pauses_persist). Frontend: workerPausesPersist store
field, load/setWorkerPausesPersist actions, toggle in SettingsModal.

src-tauri/src/commands.rs

@@ -1947,6 +1947,7 @@ pub struct FolderWorkerStates {
 
 #[tauri::command]
 pub async fn set_worker_paused(
+    app: AppHandle,
     db: State<'_, DbState>,
     worker: String,
     folder_id: i64,
@@ -1963,6 +1964,9 @@ pub async fn set_worker_paused(
         db::requeue_processing_tagging_jobs_for_folder(&conn, folder_id)
             .map_err(|e| e.to_string())?;
     }
+    if let Err(error) = persist_worker_pauses_if_enabled(&app) {
+        log::warn!("Failed to persist worker pause state: {error}");
+    }
     Ok(())
 }
 
@@ -2482,6 +2486,8 @@ pub async fn bulk_remove_tag(
 
 const TAGGING_QUEUE_SCOPE_FILE: &str = "settings/tagging_queue_scope.txt";
 const TAGGING_QUEUE_FOLDER_IDS_FILE: &str = "settings/tagging_queue_folder_ids.txt";
+const WORKER_PAUSES_PERSIST_FILE: &str = "settings/worker_pauses_persist.txt";
+const WORKER_PAUSES_FILE: &str = "settings/worker_pauses.json";
 
 #[derive(Deserialize)]
 pub struct SetTaggingQueueScopeParams {
@@ -2553,6 +2559,67 @@ pub async fn set_tagging_queue_folder_ids(
     Ok(())
 }
 
+fn worker_pause_persistence_enabled(app_dir: &Path) -> bool {
+    std::fs::read_to_string(app_dir.join(WORKER_PAUSES_PERSIST_FILE))
+        .map(|value| value.trim() == "true")
+        .unwrap_or(false)
+}
+
+fn write_worker_pause_snapshot(app_dir: &Path) -> Result<(), String> {
+    let path = app_dir.join(WORKER_PAUSES_FILE);
+    if let Some(parent) = path.parent() {
+        std::fs::create_dir_all(parent).map_err(|e| e.to_string())?;
+    }
+    let json = serde_json::to_string_pretty(&indexer::snapshot_worker_paused_states())
+        .map_err(|e| e.to_string())?;
+    std::fs::write(path, json).map_err(|e| e.to_string())
+}
+
+fn persist_worker_pauses_if_enabled(app: &AppHandle) -> Result<(), String> {
+    let app_dir = app.path().app_data_dir().map_err(|e| e.to_string())?;
+    if worker_pause_persistence_enabled(&app_dir) {
+        write_worker_pause_snapshot(&app_dir)?;
+    }
+    Ok(())
+}
+
+pub fn restore_persisted_worker_pauses(app_dir: &Path) {
+    if !worker_pause_persistence_enabled(app_dir) {
+        return;
+    }
+
+    let path = app_dir.join(WORKER_PAUSES_FILE);
+    let Ok(content) = std::fs::read_to_string(path) else {
+        return;
+    };
+    match serde_json::from_str::<indexer::PersistedPausedWorkerFolders>(&content) {
+        Ok(states) => indexer::replace_worker_paused_states(states),
+        Err(error) => log::warn!("Failed to restore persisted worker pauses: {error}"),
+    }
+}
+
+#[tauri::command]
+pub async fn get_worker_pauses_persist(app: AppHandle) -> Result<bool, String> {
+    let app_dir = app.path().app_data_dir().map_err(|e| e.to_string())?;
+    Ok(worker_pause_persistence_enabled(&app_dir))
+}
+
+#[tauri::command]
+pub async fn set_worker_pauses_persist(app: AppHandle, persist: bool) -> Result<(), String> {
+    let app_dir = app.path().app_data_dir().map_err(|e| e.to_string())?;
+    let path = app_dir.join(WORKER_PAUSES_PERSIST_FILE);
+    if let Some(parent) = path.parent() {
+        std::fs::create_dir_all(parent).map_err(|e| e.to_string())?;
+    }
+    std::fs::write(path, if persist { "true" } else { "false" }).map_err(|e| e.to_string())?;
+    if persist {
+        write_worker_pause_snapshot(&app_dir)?;
+    } else {
+        let _ = std::fs::remove_file(app_dir.join(WORKER_PAUSES_FILE));
+    }
+    Ok(())
+}
+
 // ---------------------------------------------------------------------------
 // App data folder
 // ---------------------------------------------------------------------------

src-tauri/src/indexer.rs

@@ -9,7 +9,7 @@ use crate::vector;
 use anyhow::Result;
 use notify::{RecommendedWatcher, RecursiveMode, Watcher};
 use rayon::prelude::*;
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use std::collections::{HashMap, HashSet};
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex, OnceLock};
@@ -41,6 +41,14 @@ struct PausedWorkerFolders {
     tagging: HashSet<i64>,
 }
 
+#[derive(Default, Deserialize, Serialize)]
+pub struct PersistedPausedWorkerFolders {
+    pub thumbnail: Vec<i64>,
+    pub metadata: Vec<i64>,
+    pub embedding: Vec<i64>,
+    pub tagging: Vec<i64>,
+}
+
 #[derive(Clone, Copy)]
 pub struct FolderWorkerPausedState {
     pub thumbnail: bool,
@@ -50,6 +58,41 @@ pub struct FolderWorkerPausedState {
     pub tagging: bool,
 }
 
+pub fn replace_worker_paused_states(states: PersistedPausedWorkerFolders) {
+    if let Ok(mut paused_folders) = PAUSED_WORKER_FOLDERS
+        .get_or_init(|| Mutex::new(PausedWorkerFolders::default()))
+        .lock()
+    {
+        paused_folders.thumbnail = states.thumbnail.into_iter().collect();
+        paused_folders.metadata = states.metadata.into_iter().collect();
+        paused_folders.embedding = states.embedding.into_iter().collect();
+        paused_folders.caption = HashSet::new();
+        paused_folders.tagging = states.tagging.into_iter().collect();
+    }
+}
+
+pub fn snapshot_worker_paused_states() -> PersistedPausedWorkerFolders {
+    let Ok(paused_folders) = PAUSED_WORKER_FOLDERS
+        .get_or_init(|| Mutex::new(PausedWorkerFolders::default()))
+        .lock()
+    else {
+        return PersistedPausedWorkerFolders::default();
+    };
+
+    let sorted = |set: &HashSet<i64>| {
+        let mut ids = set.iter().copied().collect::<Vec<_>>();
+        ids.sort_unstable();
+        ids
+    };
+
+    PersistedPausedWorkerFolders {
+        thumbnail: sorted(&paused_folders.thumbnail),
+        metadata: sorted(&paused_folders.metadata),
+        embedding: sorted(&paused_folders.embedding),
+        tagging: sorted(&paused_folders.tagging),
+    }
+}
+
 pub fn set_worker_paused(worker: &str, folder_id: i64, paused: bool) {
     if let Ok(mut paused_folders) = PAUSED_WORKER_FOLDERS
         .get_or_init(|| Mutex::new(PausedWorkerFolders::default()))

src-tauri/src/lib.rs

@@ -119,6 +119,7 @@ pub fn run() {
 
             let thumb_dir = app_dir.join("thumbnails");
             std::fs::create_dir_all(&thumb_dir).expect("Failed to create thumbnail dir");
+            commands::restore_persisted_worker_pauses(&app_dir);
 
             // The asset protocol scope is no longer a blanket "**": thumbnails
             // are allowed statically in tauri.conf.json, and each indexed
@@ -195,6 +196,8 @@ pub fn run() {
             commands::suggest_image_tags,
             commands::set_worker_paused,
             commands::get_worker_states,
+            commands::get_worker_pauses_persist,
+            commands::set_worker_pauses_persist,
             commands::get_tag_cloud,
             commands::get_explore_tags,
             commands::get_related_tags,