fix(downloads): harden queue and lifecycle synchronization

Serialize queue controls, make multi-item moves atomic, await stale enqueue cleanup, and guard late media and progress events. Add deterministic table sorting and regression coverage for worst-case lifecycle races.
2026-07-26 12:08:27 +00:00 · 2026-07-14 18:29:14 +03:30
parent 2d9eed99d5
commit e07182fbf2
15 changed files with 1074 additions and 321 deletions
@@ -46,18 +46,29 @@ impl DownloadCoordinator {
            .map_err(|_| "download coordinator is unavailable".to_string())
    }

-    pub async fn register_media(&self, id: String) -> Result<watch::Receiver<bool>, String> {
+    pub async fn register_media(
+        &self,
+        id: String,
+        lifecycle_generation: u64,
+    ) -> Result<watch::Receiver<bool>, String> {
        let (cancel_tx, cancel_rx) = watch::channel(false);
        self.media_tx
-            .send(MediaCmd::Register { id, cancel_tx })
+            .send(MediaCmd::Register {
+                id,
+                lifecycle_generation,
+                cancel_tx,
+            })
            .await
            .map_err(|_| "download coordinator is unavailable".to_string())?;
        Ok(cancel_rx)
    }

-    pub async fn pause_media(&self, id: String) -> Result<(), String> {
+    pub async fn pause_media(&self, id: String, lifecycle_generation: u64) -> Result<(), String> {
        self.media_tx
-            .send(MediaCmd::Pause(id))
+            .send(MediaCmd::Pause {
+                id,
+                lifecycle_generation,
+            })
            .await
            .map_err(|_| "download coordinator is unavailable".to_string())
    }
@@ -65,16 +76,27 @@ impl DownloadCoordinator {
    pub async fn pause_media_with_ack(
        &self,
        id: String,
+        lifecycle_generation: u64,
        ack: tokio::sync::oneshot::Sender<()>,
    ) -> Result<(), String> {
        self.media_tx
-            .send(MediaCmd::PauseWithAck(id, ack))
+            .send(MediaCmd::PauseWithAck {
+                id,
+                lifecycle_generation,
+                ack,
+            })
            .await
            .map_err(|_| "download coordinator is unavailable".to_string())
    }

-    pub async fn finish_media(&self, id: String) {
-        let _ = self.media_tx.send(MediaCmd::Finished(id)).await;
+    pub async fn finish_media(&self, id: String, lifecycle_generation: u64) {
+        let _ = self
+            .media_tx
+            .send(MediaCmd::Finished {
+                id,
+                lifecycle_generation,
+            })
+            .await;
    }
 }

@@ -96,11 +118,22 @@ impl CoordinatorEventSink {
 enum MediaCmd {
    Register {
        id: String,
+        lifecycle_generation: u64,
        cancel_tx: watch::Sender<bool>,
    },
-    Pause(String),
-    PauseWithAck(String, tokio::sync::oneshot::Sender<()>),
-    Finished(String),
+    Pause {
+        id: String,
+        lifecycle_generation: u64,
+    },
+    PauseWithAck {
+        id: String,
+        lifecycle_generation: u64,
+        ack: tokio::sync::oneshot::Sender<()>,
+    },
+    Finished {
+        id: String,
+        lifecycle_generation: u64,
+    },
 }

 async fn run_coordinator(
@@ -108,8 +141,8 @@ async fn run_coordinator(
    mut command_rx: mpsc::Receiver<DownloadCmd>,
    mut media_rx: mpsc::Receiver<MediaCmd>,
 ) {
-    let mut active_media = HashMap::<String, watch::Sender<bool>>::new();
-    let mut pending_media_acks = HashMap::<String, tokio::sync::oneshot::Sender<()>>::new();
+    let mut active_media = HashMap::<String, (u64, watch::Sender<bool>)>::new();
+    let mut pending_media_acks = HashMap::<String, (u64, tokio::sync::oneshot::Sender<()>)>::new();
    let mut pending_captured_urls = Vec::<String>::new();
    let mut frontend_ready = false;

@@ -146,28 +179,36 @@ async fn run_coordinator(
                    continue;
                };
                match command {
-                    MediaCmd::Register { id, cancel_tx } => {
-                        if let Some(previous) = active_media.insert(id, cancel_tx) {
+                    MediaCmd::Register { id, lifecycle_generation, cancel_tx } => {
+                        if let Some((_, previous)) = active_media.insert(id, (lifecycle_generation, cancel_tx)) {
                            let _ = previous.send(true);
                        }
                    }
-                    MediaCmd::Pause(id) => {
-                        if let Some(cancel_tx) = active_media.remove(&id) {
-                            let _ = cancel_tx.send(true);
+                    MediaCmd::Pause { id, lifecycle_generation } => {
+                        if active_media.get(&id).is_some_and(|(generation, _)| *generation == lifecycle_generation) {
+                            if let Some((_, cancel_tx)) = active_media.remove(&id) {
+                                let _ = cancel_tx.send(true);
+                            }
                        }
                    }
-                    MediaCmd::PauseWithAck(id, ack) => {
-                        if let Some(cancel_tx) = active_media.remove(&id) {
-                            let _ = cancel_tx.send(true);
-                            pending_media_acks.insert(id, ack);
+                    MediaCmd::PauseWithAck { id, lifecycle_generation, ack } => {
+                        if active_media.get(&id).is_some_and(|(generation, _)| *generation == lifecycle_generation) {
+                            if let Some((_, cancel_tx)) = active_media.remove(&id) {
+                                let _ = cancel_tx.send(true);
+                                pending_media_acks.insert(id, (lifecycle_generation, ack));
+                            }
                        } else {
                            let _ = ack.send(());
                        }
                    }
-                    MediaCmd::Finished(id) => {
-                        active_media.remove(&id);
-                        if let Some(ack) = pending_media_acks.remove(&id) {
-                            let _ = ack.send(());
+                    MediaCmd::Finished { id, lifecycle_generation } => {
+                        if active_media.get(&id).is_some_and(|(generation, _)| *generation == lifecycle_generation) {
+                            active_media.remove(&id);
+                        }
+                        if pending_media_acks.get(&id).is_some_and(|(generation, _)| *generation == lifecycle_generation) {
+                            if let Some((_, ack)) = pending_media_acks.remove(&id) {
+                                let _ = ack.send(());
+                            }
                        }
                    }
                }
@@ -175,7 +216,7 @@ async fn run_coordinator(
        }
    }

-    for (_, cancel_tx) in active_media {
+    for (_, (_, cancel_tx)) in active_media {
        let _ = cancel_tx.send(true);
    }
 }
@@ -251,4 +292,29 @@ mod tests {
            DownloadEvent::CapturedUrls("https://example.com/startup.zip".to_string())
        );
    }
+
+    #[tokio::test]
+    async fn stale_media_finish_cannot_remove_a_newer_lifecycle() {
+        let (coordinator, _events) = DownloadCoordinator::spawn_headless();
+        let mut old_cancel = coordinator.register_media("same-id".to_string(), 1).await.unwrap();
+        let mut new_cancel = coordinator.register_media("same-id".to_string(), 2).await.unwrap();
+
+        tokio::time::timeout(Duration::from_secs(1), old_cancel.changed())
+            .await
+            .unwrap()
+            .unwrap();
+        coordinator.finish_media("same-id".to_string(), 1).await;
+
+        let (ack_tx, ack_rx) = tokio::sync::oneshot::channel();
+        coordinator
+            .pause_media_with_ack("same-id".to_string(), 2, ack_tx)
+            .await
+            .unwrap();
+        coordinator.finish_media("same-id".to_string(), 2).await;
+        tokio::time::timeout(Duration::from_secs(1), ack_rx)
+            .await
+            .unwrap()
+            .unwrap();
+        assert!(*new_cancel.borrow_and_update());
+    }
 }
@@ -3357,6 +3357,11 @@ async fn pause_download(

    let _control_guard = state.queue_manager.acquire_aria2_control(&id).await;
    let active_kind = state.queue_manager.active_kind(&id).await;
+    let media_lifecycle_generation = state
+        .queue_manager
+        .registered_lifecycle_generation(&id)
+        .await
+        .unwrap_or_default();
    let removed_pending = state.queue_manager.remove_from_pending(&id).await;

    let gid = state.queue_manager.aria2_gid_for_download(&id);
@@ -3447,7 +3452,7 @@ async fn pause_download(
    if matches!(active_kind, Some(crate::queue::TaskKind::Media)) {
        state
            .download_coordinator
-            .pause_media_with_ack(id.clone(), tx)
+            .pause_media_with_ack(id.clone(), media_lifecycle_generation, tx)
            .await?;
    } else {
        let _ = tx.send(());
@@ -3498,6 +3503,7 @@ async fn resume_download(
        "paused" => {
            let control_epoch = state.queue_manager.next_aria2_control_epoch(&id).await;
            state.queue_manager.allow_aria2_retries(&id).await;
+            state.queue_manager.reset_aria2_retry_strikes(&id).await;
            use tauri::Emitter;
            let _ = app_handle.emit(
                "download-state",
@@ -3713,6 +3719,11 @@ async fn remove_download(
    let _control_guard = state.queue_manager.acquire_aria2_control(&id).await;

    let active_kind = state.queue_manager.active_kind(&id).await;
+    let media_lifecycle_generation = state
+        .queue_manager
+        .registered_lifecycle_generation(&id)
+        .await
+        .unwrap_or_default();
    state.queue_manager.remove_from_pending(&id).await;

    state.queue_manager.next_aria2_control_epoch(&id).await;
@@ -3748,7 +3759,7 @@ async fn remove_download(
        if matches!(active_kind, Some(crate::queue::TaskKind::Media)) {
            state
                .download_coordinator
-                .pause_media_with_ack(id.clone(), tx)
+                .pause_media_with_ack(id.clone(), media_lifecycle_generation, tx)
                .await?;
        } else {
            let _ = tx.send(());
@@ -3864,6 +3875,11 @@ async fn detach_download_for_reconfigure(
    log::info!("detach_download_for_reconfigure called for id: {}", id);
    let _control_guard = state.queue_manager.acquire_aria2_control(&id).await;
    let active_kind = state.queue_manager.active_kind(&id).await;
+    let media_lifecycle_generation = state
+        .queue_manager
+        .registered_lifecycle_generation(&id)
+        .await
+        .unwrap_or_default();
    state.queue_manager.remove_from_pending(&id).await;
    state.queue_manager.next_aria2_control_epoch(&id).await;
    state.queue_manager.cancel_aria2_retries(&id).await;
@@ -3908,7 +3924,7 @@ async fn detach_download_for_reconfigure(
        if matches!(active_kind, Some(crate::queue::TaskKind::Media)) {
            state
                .download_coordinator
-                .pause_media_with_ack(id.clone(), tx)
+                .pause_media_with_ack(id.clone(), media_lifecycle_generation, tx)
                .await?;
        } else {
            let _ = tx.send(()); // Fallback if no task exists
@@ -4461,6 +4477,19 @@ async fn move_in_queue(
        .await)
 }

+#[tauri::command]
+async fn move_many_in_queue(
+    state: tauri::State<'_, AppState>,
+    ids: Vec<String>,
+    queue_id: String,
+    direction: crate::ipc::QueueDirection,
+) -> Result<Vec<String>, AppError> {
+    Ok(state
+        .queue_manager
+        .move_many_in_queue(&ids, &queue_id, direction)
+        .await)
+}
+
 #[tauri::command]
 async fn remove_from_queue(
    app_handle: tauri::AppHandle,
@@ -6717,7 +6746,7 @@ pub fn run() {
            check_file_exists, toggle_tray_icon, set_extension_pairing_token,
            get_extension_server_port, set_extension_frontend_ready, set_concurrent_limit, set_global_speed_limit, remove_download,
            detach_download_for_reconfigure,
-            enqueue_download, enqueue_many, cancel_enqueue_generation, move_in_queue, remove_from_queue, get_pending_order,
+            enqueue_download, enqueue_many, cancel_enqueue_generation, move_in_queue, move_many_in_queue, remove_from_queue, get_pending_order,
            commands::reveal_in_file_manager, commands::open_downloaded_file,
            parity::get_system_proxy, parity::get_file_category, parity::check_for_updates, parity::is_supported_media, parity::get_supported_media_domains,
            parity::create_category_directories,
@@ -73,6 +73,9 @@ pub struct QueuedTask {
    pub queue_id: String,
    pub kind: TaskKind,
    pub payload: SpawnPayload,
+    /// Frontend lifecycle generation that owns this sidecar and its permit.
+    /// Manual internal/test tasks use generation 0.
+    pub lifecycle_generation: u64,
 }

 /// Args mirroring start_download / start_media_download. Kept untyped-loose
@@ -120,17 +123,24 @@ pub trait SidecarSpawner: Send + Sync + 'static {

    /// Run a media download to completion. The permit is parked for the full
    /// duration; release is handled by QueueManager on the runner's exit.
-    async fn run_media(&self, id: &str, payload: &SpawnPayload) -> Result<(), String>;
+    async fn run_media(
+        &self,
+        id: &str,
+        payload: &SpawnPayload,
+        lifecycle_generation: u64,
+    ) -> Result<(), String>;
 }

 /// The centralized concurrency gatekeeper. One instance lives in AppState.
 pub struct QueueManager<R: tauri::Runtime = tauri::Wry> {
    registered_ids: Mutex<HashSet<String>>,
+    registered_lifecycle_generations: Mutex<HashMap<String, u64>>,
    enqueue_cancellations: Mutex<HashMap<String, u64>>,
    enqueue_generations: Mutex<HashMap<String, u64>>,
    pending: Mutex<VecDeque<QueuedTask>>,
    semaphore: Arc<Semaphore>,
    active_permits: Mutex<HashMap<String, OwnedSemaphorePermit>>,
+    active_permit_generations: Mutex<HashMap<String, u64>>,
    active_kinds: Mutex<HashMap<String, TaskKind>>,
    target_capacity: AtomicUsize,
    slots_to_retire: AtomicUsize,
@@ -197,11 +207,13 @@ impl<R: tauri::Runtime> QueueManager<R> {
    ) -> Self {
        Self {
            registered_ids: Mutex::new(HashSet::new()),
+            registered_lifecycle_generations: Mutex::new(HashMap::new()),
            enqueue_cancellations: Mutex::new(HashMap::new()),
            enqueue_generations: Mutex::new(HashMap::new()),
            pending: Mutex::new(VecDeque::new()),
            semaphore: Arc::new(Semaphore::new(capacity)),
            active_permits: Mutex::new(HashMap::new()),
+            active_permit_generations: Mutex::new(HashMap::new()),
            active_kinds: Mutex::new(HashMap::new()),
            target_capacity: AtomicUsize::new(capacity),
            slots_to_retire: AtomicUsize::new(0),
@@ -237,6 +249,7 @@ impl<R: tauri::Runtime> QueueManager<R> {
    /// Explicitly release a backend registry id (e.g. on un-resumable false paths, removals, or detach).
    pub async fn release_registered_id(&self, id: &str) {
        self.registered_ids.lock().await.remove(id);
+        self.registered_lifecycle_generations.lock().await.remove(id);
        // A released lifecycle cannot be resumed by a delayed retry worker.
        // Epoch checks remain the authoritative guard; removing this marker
        // prevents terminal downloads from accumulating cancellation entries.
@@ -247,6 +260,40 @@ impl<R: tauri::Runtime> QueueManager<R> {
        self.registered_ids.lock().await.contains(id)
    }

+    pub async fn registered_lifecycle_generation(&self, id: &str) -> Option<u64> {
+        self.registered_lifecycle_generations
+            .lock()
+            .await
+            .get(id)
+            .copied()
+    }
+
+    async fn is_registered_generation(&self, id: &str, generation: u64) -> bool {
+        self.registered_lifecycle_generations
+            .lock()
+            .await
+            .get(id)
+            .copied()
+            == Some(generation)
+    }
+
+    async fn release_registered_id_for_generation(&self, id: &str, generation: u64) {
+        let released = {
+            let mut registered = self.registered_ids.lock().await;
+            let mut generations = self.registered_lifecycle_generations.lock().await;
+            if generations.get(id).copied() == Some(generation) {
+                registered.remove(id);
+                generations.remove(id);
+                true
+            } else {
+                false
+            }
+        };
+        if released {
+            self.aria2_retry_cancelled.lock().await.remove(id);
+        }
+    }
+
    /// Reject an in-flight enqueue generation if a newer UI action supersedes it.
    pub async fn cancel_enqueue_generation(&self, id: &str, generation: u64) {
        let mut cancellations = self.enqueue_cancellations.lock().await;
@@ -282,6 +329,10 @@ impl<R: tauri::Runtime> QueueManager<R> {
            return Err("Duplicate task".to_string());
        }
        registered.insert(id.to_string());
+        self.registered_lifecycle_generations
+            .lock()
+            .await
+            .insert(id.to_string(), generation);
        generations.insert(id.to_string(), generation);
        Ok(previous_generation)
    }
@@ -298,6 +349,7 @@ impl<R: tauri::Runtime> QueueManager<R> {
            return;
        }
        registered.remove(id);
+        self.registered_lifecycle_generations.lock().await.remove(id);
        match previous_generation {
            Some(previous) => {
                generations.insert(id.to_string(), previous);
@@ -459,6 +511,13 @@ impl<R: tauri::Runtime> QueueManager<R> {
            .insert(id.to_string(), permit);
    }

+    async fn tag_permit_generation(&self, id: &str, generation: u64) {
+        self.active_permit_generations
+            .lock()
+            .await
+            .insert(id.to_string(), generation);
+    }
+
    pub async fn active_kind(&self, id: &str) -> Option<TaskKind> {
        self.active_kinds.lock().await.get(id).cloned()
    }
@@ -492,12 +551,30 @@ impl<R: tauri::Runtime> QueueManager<R> {

    pub async fn release_permit(&self, id: &str) {
        let removed = self.active_permits.lock().await.remove(id).is_some();
+        self.active_permit_generations.lock().await.remove(id);
        self.active_kinds.lock().await.remove(id);
        if removed {
            self.notify.notify_one();
        }
    }

+    async fn release_permit_for_generation(&self, id: &str, generation: u64) {
+        let removed = {
+            let mut permits = self.active_permits.lock().await;
+            let mut generations = self.active_permit_generations.lock().await;
+            if generations.get(id).copied() == Some(generation) {
+                generations.remove(id);
+                permits.remove(id).is_some()
+            } else {
+                false
+            }
+        };
+        if removed {
+            self.active_kinds.lock().await.remove(id);
+            self.notify.notify_one();
+        }
+    }
+
    pub async fn has_active_permit(&self, id: &str) -> bool {
        self.active_permits.lock().await.contains_key(id)
    }
@@ -607,10 +684,12 @@ impl<R: tauri::Runtime> QueueManager<R> {

    async fn dispatch_one(self: Arc<Self>, permit: OwnedSemaphorePermit, task: QueuedTask) {
        let id = task.id.clone();
+        let lifecycle_generation = task.lifecycle_generation;
        // Park the permit BEFORE spawning. Uniform parking:
        // aria2's RPC returns instantly, so the permit must outlive the
        // dispatch_one call. Media runners release on exit.
        self.park_permit(&id, permit).await;
+        self.tag_permit_generation(&id, lifecycle_generation).await;
        self.active_kinds
            .lock()
            .await
@@ -693,30 +772,55 @@ impl<R: tauri::Runtime> QueueManager<R> {
                let payload = task.payload.clone();
                let id_for_task = id.clone();
                tauri::async_runtime::spawn(async move {
-                    let outcome = this.spawner.run_media(&id_for_task, &payload).await;
-                    this.finish_runner(&id_for_task, outcome).await;
+                    let outcome = this
+                        .spawner
+                        .run_media(&id_for_task, &payload, lifecycle_generation)
+                        .await;
+                    this.finish_runner(&id_for_task, lifecycle_generation, outcome)
+                        .await;
                });
            }
        }
    }

    /// Terminal handler for non-aria2 transfers. Emits state and frees the permit.
-    /// Does not emit or release anything on intentional MEDIA_RUN_CANCELLED.
+    /// Intentional cancellation is silent, but still releases backend ownership.
    /// Note: `id` is the frontend download UUID, which survives indefinitely as
    /// the terminal state.
-    async fn finish_runner(self: Arc<Self>, id: &str, outcome: Result<(), String>) {
+    async fn finish_runner(
+        self: Arc<Self>,
+        id: &str,
+        lifecycle_generation: u64,
+        outcome: Result<(), String>,
+    ) {
+        if !self.is_registered_generation(id, lifecycle_generation).await {
+            log::info!(
+                "media runner [{}]: ignoring stale terminal outcome for lifecycle {}",
+                id,
+                lifecycle_generation
+            );
+            self.release_permit_for_generation(id, lifecycle_generation).await;
+            return;
+        }
+
        match outcome {
            Ok(()) => {
                self.emit_state(id, DownloadStatus::Completed);
-                self.release_registered_id(id).await;
+                self.release_registered_id_for_generation(id, lifecycle_generation)
+                    .await;
+            }
+            Err(error) if error == MEDIA_RUN_CANCELLED => {
+                self.release_registered_id_for_generation(id, lifecycle_generation)
+                    .await;
            }
-            Err(error) if error == MEDIA_RUN_CANCELLED => {}
            Err(error) => {
                self.emit_failed(id, error);
-                self.release_registered_id(id).await;
+                self.release_registered_id_for_generation(id, lifecycle_generation)
+                    .await;
            }
        }
-        self.release_permit(id).await;
+        self.release_permit_for_generation(id, lifecycle_generation)
+            .await;
    }

    fn emit_failed(&self, id: &str, error: String) {
@@ -852,6 +956,13 @@ impl<R: tauri::Runtime> QueueManager<R> {
        self.aria2_retry_cancelled.lock().await.remove(id);
    }

+    /// A user-initiated resume starts a new retry lifecycle while retaining
+    /// the paused Aria2 payload/GID. Reset only the strike budget here; the
+    /// payload is still needed for the same-GID resume path.
+    pub async fn reset_aria2_retry_strikes(&self, id: &str) {
+        self.aria2_retry_strikes.lock().await.remove(id);
+    }
+
    async fn finish_aria2_retry(&self, id: &str, gid: &str, retry_epoch: u64) {
        self.release_aria2_retry_inflight(id, retry_epoch).await;
        self.aria2_retrying_gids.lock().await.remove(gid);
@@ -1276,6 +1387,20 @@ impl<R: tauri::Runtime> QueueManager<R> {
        id: &str,
        queue_id: &str,
        direction: QueueDirection,
+    ) -> Vec<String> {
+        self.move_many_in_queue(&[id.to_string()], queue_id, direction)
+            .await
+    }
+
+    /// Atomically move a selected block of pending tasks up or down. The
+    /// frontend uses the same block semantics for multi-selection, so keeping
+    /// the operation under one pending-list lock prevents partial RPC moves
+    /// from leaving the backend in a different order than the UI.
+    pub async fn move_many_in_queue(
+        &self,
+        ids: &[String],
+        queue_id: &str,
+        direction: QueueDirection,
    ) -> Vec<String> {
        let mut pending = self.pending.lock().await;
        let queue_positions = pending
@@ -1283,22 +1408,46 @@ impl<R: tauri::Runtime> QueueManager<R> {
            .enumerate()
            .filter_map(|(index, task)| (task.queue_id == queue_id).then_some(index))
            .collect::<Vec<_>>();
-        let queue_pos = queue_positions
+        let selected_positions = queue_positions
            .iter()
-            .position(|index| pending[*index].id == id);
-        if let Some(queue_pos) = queue_pos {
-            let target = match direction {
-                QueueDirection::Up => queue_pos.checked_sub(1),
-                QueueDirection::Down => {
-                    if queue_pos + 1 < queue_positions.len() {
-                        Some(queue_pos + 1)
-                    } else {
-                        None
-                    }
-                }
+            .enumerate()
+            .filter_map(|(position, index)| ids.iter().any(|id| id == &pending[*index].id).then_some(position))
+            .collect::<Vec<_>>();
+
+        if !selected_positions.is_empty() {
+            let queue_tasks = queue_positions
+                .iter()
+                .map(|index| pending[*index].clone())
+                .collect::<Vec<_>>();
+            let selected_ids = ids.iter().collect::<HashSet<_>>();
+            let selected_tasks = queue_tasks
+                .iter()
+                .filter(|task| selected_ids.contains(&task.id))
+                .cloned()
+                .collect::<Vec<_>>();
+            let unselected_tasks = queue_tasks
+                .iter()
+                .filter(|task| !selected_ids.contains(&task.id))
+                .cloned()
+                .collect::<Vec<_>>();
+
+            let first_selected = *selected_positions.first().unwrap();
+            let last_selected = *selected_positions.last().unwrap();
+            let selected_count = selected_tasks.len();
+            let insert_index = match direction {
+                QueueDirection::Up => first_selected.saturating_sub(1),
+                QueueDirection::Down => (last_selected + 1)
+                    .saturating_sub(selected_count)
+                    .saturating_add(1)
+                    .min(unselected_tasks.len()),
            };
-            if let Some(target) = target {
-                pending.swap(queue_positions[queue_pos], queue_positions[target]);
+            let mut reordered = Vec::with_capacity(queue_tasks.len());
+            reordered.extend_from_slice(&unselected_tasks[..insert_index]);
+            reordered.extend(selected_tasks);
+            reordered.extend_from_slice(&unselected_tasks[insert_index..]);
+
+            for (queue_index, pending_index) in queue_positions.iter().enumerate() {
+                pending[*pending_index] = reordered[queue_index].clone();
            }
        }
        pending
@@ -1740,11 +1889,16 @@ impl SidecarSpawner for ProductionSpawner {
        crate::ensure_aria2_gid_result("unpause", gid, &resumed)
    }

-    async fn run_media(&self, id: &str, payload: &SpawnPayload) -> Result<(), String> {
+    async fn run_media(
+        &self,
+        id: &str,
+        payload: &SpawnPayload,
+        lifecycle_generation: u64,
+    ) -> Result<(), String> {
        let state = self.app_handle.state::<crate::AppState>();
        let mut cancel_rx = state
            .download_coordinator
-            .register_media(id.to_string())
+            .register_media(id.to_string(), lifecycle_generation)
            .await?;
        let outcome = crate::start_media_download_internal(
            self.app_handle.clone(),
@@ -1777,7 +1931,7 @@ impl SidecarSpawner for ProductionSpawner {
        }
        let _ = state
            .download_coordinator
-            .finish_media(id.to_string())
+            .finish_media(id.to_string(), lifecycle_generation)
            .await;
        outcome.map(|_| ())
    }
@@ -1823,6 +1977,11 @@ impl EnqueueItem {
            id,
            queue_id: self.queue_id,
            kind,
+            lifecycle_generation: self
+                .lifecycle_generation
+                .as_deref()
+                .and_then(|generation| generation.parse().ok())
+                .unwrap_or_default(),
            payload: SpawnPayload {
                url: self.url,
                destination: self.destination,
@@ -63,7 +63,7 @@ impl SidecarSpawner for DelayedAria2Spawner {
        Ok(())
    }

-    async fn run_media(&self, _id: &str, _payload: &SpawnPayload) -> Result<(), String> {
+    async fn run_media(&self, _id: &str, _payload: &SpawnPayload, _generation: u64) -> Result<(), String> {
        unreachable!("media is not used by delayed aria2 tests")
    }
 }
@@ -86,7 +86,7 @@ impl SidecarSpawner for FailFirstAria2Spawner {
        Ok(())
    }

-    async fn run_media(&self, _id: &str, _payload: &SpawnPayload) -> Result<(), String> {
+    async fn run_media(&self, _id: &str, _payload: &SpawnPayload, _generation: u64) -> Result<(), String> {
        unreachable!("media is not used by fail-first aria2 tests")
    }
 }
@@ -109,7 +109,7 @@ impl firelink_lib::queue::SidecarSpawner for CountingSpawner {
    async fn remove_uri(&self, _gid: &str) -> Result<(), String> {
        Ok(())
    }
-    async fn run_media(&self, _id: &str, _payload: &SpawnPayload) -> Result<(), String> {
+    async fn run_media(&self, _id: &str, _payload: &SpawnPayload, _generation: u64) -> Result<(), String> {
        self.media_calls.fetch_add(1, Ordering::SeqCst);
        Ok(())
    }
@@ -131,6 +131,7 @@ fn sample_task(id: &str) -> QueuedTask {
        id: id.to_string(),
        queue_id: "main".to_string(),
        kind: TaskKind::Aria2,
+        lifecycle_generation: 0,
        payload: SpawnPayload::default(),
    }
 }
@@ -498,6 +499,7 @@ fn aria2_task(id: &str) -> QueuedTask {
        id: id.to_string(),
        queue_id: "main".to_string(),
        kind: TaskKind::Aria2,
+        lifecycle_generation: 0,
        payload: SpawnPayload::default(),
    }
 }
@@ -507,6 +509,7 @@ fn media_task(id: &str) -> QueuedTask {
        id: id.to_string(),
        queue_id: "main".to_string(),
        kind: TaskKind::Media,
+        lifecycle_generation: 0,
        payload: SpawnPayload::default(),
    }
 }
@@ -525,7 +528,7 @@ impl SidecarSpawner for FixedMediaSpawner {
        unreachable!("aria2 is not used by media terminal-state tests")
    }

-    async fn run_media(&self, _id: &str, _payload: &SpawnPayload) -> Result<(), String> {
+    async fn run_media(&self, _id: &str, _payload: &SpawnPayload, _generation: u64) -> Result<(), String> {
        self.outcome.clone()
    }
 }
@@ -590,6 +593,7 @@ async fn media_cancellation_does_not_emit_completed() {
    assert!(!statuses.iter().any(|status| status == "failed"));
    assert!(!statuses.iter().any(|status| status == "completed"));
    assert_eq!(manager.available_permits(), 1);
+    assert!(!manager.is_registered("media-cancelled").await);

    dispatcher.abort();
 }
@@ -1079,6 +1083,28 @@ async fn move_up_down_reorders_pending() {
    assert_eq!(mgr_arc.pending_order(None).await, vec!["c", "a", "b"]);
 }

+#[tokio::test]
+async fn multi_move_reorders_selected_items_as_one_atomic_block() {
+    use firelink_lib::ipc::QueueDirection;
+
+    let (mgr, _spawner) = make_manager(3);
+    for id in ["a", "b", "c", "d", "e"] {
+        mgr.push(sample_task(id)).await.unwrap();
+    }
+
+    let selected = vec!["b".to_string(), "d".to_string()];
+    assert_eq!(
+        mgr.move_many_in_queue(&selected, "main", QueueDirection::Up)
+            .await,
+        vec!["b", "d", "a", "c", "e"]
+    );
+    assert_eq!(
+        mgr.move_many_in_queue(&selected, "main", QueueDirection::Down)
+            .await,
+        vec!["a", "b", "d", "c", "e"]
+    );
+}
+
 #[tokio::test]
 async fn moving_one_queue_does_not_reorder_another_queue() {
    use firelink_lib::ipc::QueueDirection;
@@ -1,4 +1,4 @@
-import { initMediaDomains, isActiveDownloadStatus, normalizeSpeedLimitForBackend } from './utils/downloads';
+import { initMediaDomains, isActiveDownloadStatus, isTransferActiveStatus, normalizeSpeedLimitForBackend } from './utils/downloads';
 import { schedulerCompletionState } from './utils/schedulerCompletion';
 import { useCallback, useEffect, useRef, useState } from "react";
 import { Sidebar, SidebarFilter } from "./components/Sidebar";
@@ -112,7 +112,7 @@ function App() {
  const logsEnabled = useSettingsStore(state => state.logsEnabled);
  const extensionPairingToken = useSettingsStore(state => state.extensionPairingToken);
  const downloads = useDownloadStore(state => state.downloads);
-  const activeDownloadCount = downloads.filter(download => download.status === 'downloading').length;
+  const activeDownloadCount = downloads.filter(download => isTransferActiveStatus(download.status)).length;
  const queuedCount = downloads.filter(download =>
    download.status === 'queued' || download.status === 'staged'
  ).length;
@@ -124,11 +124,7 @@ function App() {
  const pendingPostActionTimer = useRef<number | null>(null);
  const maxConcurrentDownloads = useSettingsStore(state => state.maxConcurrentDownloads);
  const preventsSleepWhileDownloading = useSettingsStore(state => state.preventsSleepWhileDownloading);
-  const activeTransferCount = downloads.filter(download =>
-    download.status === 'downloading' ||
-    download.status === 'processing' ||
-    download.status === 'retrying'
-  ).length;
+  const activeTransferCount = downloads.filter(download => isTransferActiveStatus(download.status)).length;
  const { addToast } = useToast();
  const isMacUserAgent = navigator.userAgent.includes('Mac');
  const usesCustomWindowControls = !isMacUserAgent && platform.os !== 'macos';
@@ -1,4 +1,4 @@
-import React, { useState, useEffect, useRef } from 'react';
+import React, { useState, useEffect, useMemo, useRef } from 'react';
 import { useDownloadStore, DownloadItem } from '../store/useDownloadStore';
 import { useToast } from '../contexts/ToastContext';
 import { useSettingsStore } from '../store/useSettingsStore';
@@ -17,8 +17,13 @@ import {
  canStartDownload,
  startActionLabel
 } from '../utils/downloadActions';
-import { isActiveDownloadStatus } from '../utils/downloads';
+import { isActiveDownloadStatus, isTransferActiveStatus } from '../utils/downloads';
 import { readClipboardDownloadUrls } from '../utils/clipboard';
+import {
+  sortDownloads,
+  type DownloadSortColumn,
+  type DownloadSortConfig
+} from '../utils/downloadTableSorting';

 interface DownloadTableProps {
  filter: SidebarFilter;
@@ -46,7 +51,11 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
  const [animationParent] = useAutoAnimate<HTMLDivElement>();
  const [selectedIds, setSelectedIds] = useState<Set<string>>(new Set());
  const [lastSelectedId, setLastSelectedId] = useState<string | null>(null);
-  const [sortConfig, setSortConfig] = useState<{ column: string; direction: 'asc' | 'desc' } | null>({ column: 'Date Added', direction: 'desc' });
+  const [sortConfig, setSortConfig] = useState<DownloadSortConfig>({ column: 'Date Added', direction: 'desc' });
+  const [queueSortConfig, setQueueSortConfig] = useState<DownloadSortConfig | null>(null);
+  const selectedIdsRef = useRef(selectedIds);
+  const sortedDownloadsRef = useRef<DownloadItem[]>([]);
+  selectedIdsRef.current = selectedIds;
  const [columnWidths, setColumnWidths] = useState(() => {
    try {
      const stored = JSON.parse(window.localStorage.getItem(COLUMN_WIDTHS_STORAGE_KEY) || 'null');
@@ -110,15 +119,15 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
      if (!isInput) {
        if ((e.key === 'a' || e.key === 'A') && (e.metaKey || e.ctrlKey)) {
          e.preventDefault();
-          const allIds = sortedDownloads.map(d => d.id);
+          const allIds = sortedDownloadsRef.current.map(d => d.id);
          setSelectedIds(new Set(allIds));
          return;
        }
        
        if (e.key === 'Delete' || e.key === 'Backspace') {
          if (!activeEl || !activeEl.closest('.sidebar-inner')) {
-            if (selectedIds.size > 0) {
-              handleDelete(Array.from(selectedIds));
+            if (selectedIdsRef.current.size > 0) {
+              handleDelete(Array.from(selectedIdsRef.current));
            }
          }
        }
@@ -126,7 +135,7 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
    };
    window.addEventListener('keydown', handleKeyDown);
    return () => window.removeEventListener('keydown', handleKeyDown);
-  }, [selectedIds]);
+  }, []);


  const showInteractionError = (message: string, error: unknown) => {
@@ -192,43 +201,24 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
    openProperties(item.id);
  };

-  const filteredDownloads = downloads.filter((d: DownloadItem) => {
-    if (filter.startsWith('queue:')) {
+  const isQueueFilter = filter.startsWith('queue:');
+  const filteredDownloads = useMemo(() => downloads.filter((d: DownloadItem) => {
+    if (isQueueFilter) {
      return d.queueId === filter.replace('queue:', '') && d.status !== 'completed';
    }
    switch (filter) {
      case 'all': return true;
-      case 'active': return d.status === 'downloading';
+      case 'active': return isTransferActiveStatus(d.status);
      case 'completed': return d.status === 'completed';
      case 'unfinished': return d.status !== 'completed';
      default: return d.category === filter;
    }
-  });
+  }), [downloads, filter, isQueueFilter]);

-  const parseSpeed = (speedStr?: string) => {
-    if (!speedStr || speedStr === '-') return 0;
-    const val = parseFloat(speedStr);
-    if (speedStr.includes('KB/s')) return val * 1024;
-    if (speedStr.includes('MB/s')) return val * 1024 * 1024;
-    if (speedStr.includes('GB/s')) return val * 1024 * 1024 * 1024;
-    return val;
-  };
-
-  const parseEta = (etaStr?: string) => {
-    if (!etaStr || etaStr === '-') return Infinity;
-    let seconds = 0;
-    const hours = etaStr.match(/(\d+)h/);
-    const minutes = etaStr.match(/(\d+)m/);
-    const secs = etaStr.match(/(\d+)s/);
-    if (hours) seconds += parseInt(hours[1]) * 3600;
-    if (minutes) seconds += parseInt(minutes[1]) * 60;
-    if (secs) seconds += parseInt(secs[1]);
-    return seconds;
-  };
-
-  // Sort by queue position when viewing a specific queue so the visual
-  // order matches the queue order and move-up/down buttons reflect reality.
-  const sortedDownloads = filter.startsWith('queue:')
+  // Queue views use the persisted queue order until the user explicitly sorts
+  // a column. This keeps move-up/down controls truthful while still making
+  // every header a working sort target.
+  const sortedDownloads = useMemo(() => isQueueFilter && !queueSortConfig
    ? [...filteredDownloads].sort((left, right) => {
        const leftActive = isActiveDownloadStatus(left.status) && left.status !== 'queued';
        const rightActive = isActiveDownloadStatus(right.status) && right.status !== 'queued';
@@ -236,40 +226,26 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
        if (leftActive && !rightActive) return -1;
        if (!leftActive && rightActive) return 1;
        
-        return (left.queuePosition ?? 0) - (right.queuePosition ?? 0);
+        const positionComparison = (left.queuePosition ?? Number.MAX_SAFE_INTEGER) -
+          (right.queuePosition ?? Number.MAX_SAFE_INTEGER);
+        return positionComparison || left.id.localeCompare(right.id);
      })
-    : sortConfig
-      ? [...filteredDownloads].sort((a, b) => {
-          const aUnfinished = a.status !== 'completed';
-          const bUnfinished = b.status !== 'completed';
+    : sortDownloads(filteredDownloads, isQueueFilter ? queueSortConfig! : sortConfig),
+    [filteredDownloads, isQueueFilter, queueSortConfig, sortConfig]);
+  sortedDownloadsRef.current = sortedDownloads;

-          if (aUnfinished && !bUnfinished) return -1;
-          if (!aUnfinished && bUnfinished) return 1;
+  useEffect(() => {
+    const visibleIds = new Set(sortedDownloads.map(download => download.id));
+    setSelectedIds(current => {
+      const next = new Set(Array.from(current).filter(id => visibleIds.has(id)));
+      return next.size === current.size ? current : next;
+    });
+    setLastSelectedId(current => current && visibleIds.has(current) ? current : null);
+  }, [sortedDownloads]);

-          let comparison = 0;
-          switch (sortConfig.column) {
-            case 'File Name':
-              comparison = (a.fileName || a.url || '').localeCompare(b.fileName || b.url || '');
-              break;
-            case 'Size':
-              comparison = parseInt(a.size || '0', 10) - parseInt(b.size || '0', 10);
-              break;
-            case 'Status':
-              comparison = a.status.localeCompare(b.status);
-              break;
-            case 'Speed':
-              comparison = parseSpeed(a.speed) - parseSpeed(b.speed);
-              break;
-            case 'ETA':
-              comparison = parseEta(a.eta) - parseEta(b.eta);
-              break;
-            case 'Date Added':
-              comparison = new Date(a.dateAdded || 0).getTime() - new Date(b.dateAdded || 0).getTime();
-              break;
-          }
-          return sortConfig.direction === 'asc' ? comparison : -comparison;
-        })
-      : filteredDownloads;
+  useEffect(() => {
+    setQueueSortConfig(null);
+  }, [filter, isQueueFilter]);
  const handleItemClick = (e: React.MouseEvent, item: DownloadItem) => {
    if (e.detail === 2) {
      handleDownloadDoubleClick(item);
@@ -312,15 +288,17 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
    setContextMenu(menu);
  };

-  const handleSort = (column: string) => {
-    if (filter.startsWith('queue:')) return; // Disable custom sorting in queues
-    setSortConfig(current => {
-      if (current?.column === column) {
-        if (current.direction === 'desc') return null; // Reset sort
-        return { column, direction: 'desc' };
-      }
-      return { column, direction: 'asc' };
-    });
+  const handleSort = (column: DownloadSortColumn) => {
+    const update = (current: DownloadSortConfig | null): DownloadSortConfig =>
+      current?.column === column
+        ? { column, direction: current.direction === 'asc' ? 'desc' : 'asc' }
+        : { column, direction: 'asc' };
+
+    if (isQueueFilter) {
+      setQueueSortConfig(update);
+    } else {
+      setSortConfig(current => update(current));
+    }
  };


@@ -356,8 +334,25 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
    }
  };

-  const handleResume = (item: DownloadItem) => {
-    useDownloadStore.getState().resumeDownload(item.id);
+  const handleResume = async (item: DownloadItem) => {
+    try {
+      const resumed = await useDownloadStore.getState().resumeDownload(item.id);
+      if (!resumed) {
+        throw new Error('The backend rejected the start/resume request.');
+      }
+    } catch (error) {
+      console.error("Failed to resume:", error);
+      showInteractionError(`Could not resume ${item.fileName}`, error);
+    }
+  };
+
+  const resumeItemsSequentially = async (items: DownloadItem[]) => {
+    for (const item of items) {
+      const current = useDownloadStore.getState().downloads.find(download => download.id === item.id);
+      if (current && canStartDownload(current.status)) {
+        await handleResume(current);
+      }
+    }
  };

  const handleDelete = (ids: string | string[]) => {
@@ -449,9 +444,7 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
            className="main-control-button" 
            disabled={sortedDownloads.length === 0}
            onClick={() => {
-              sortedDownloads
-                .filter(d => canStartDownload(d.status))
-                .forEach(d => handleResume(d));
+              void resumeItemsSequentially(sortedDownloads.filter(d => canStartDownload(d.status)));
            }}
            title="Resume All"
          >
@@ -497,13 +490,15 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
            {['File Name', 'Size', 'Status', 'Speed', 'ETA', 'Date Added'].map((label, index) => (
              <div 
                key={label} 
-                className={`${index === 5 ? 'download-cell-right' : ''} ${filter.startsWith('queue:') ? 'opacity-70 cursor-default' : 'cursor-pointer hover:text-text-primary transition-colors'} flex items-center justify-between`}
-                onClick={() => handleSort(label)}
+                className={`${index === 5 ? 'download-cell-right' : ''} cursor-pointer hover:text-text-primary transition-colors flex items-center justify-between`}
+                onClick={() => handleSort(label as DownloadSortColumn)}
              >
                <div className="flex items-center gap-1 w-full h-full select-none">
                  <span>{label}</span>
-                  {sortConfig?.column === label && (
-                    sortConfig.direction === 'asc' ? <ChevronUp size={14} /> : <ChevronDown size={14} />
+                  {(isQueueFilter ? queueSortConfig : sortConfig)?.column === label && (
+                    (isQueueFilter ? queueSortConfig : sortConfig)?.direction === 'asc'
+                      ? <ChevronUp size={14} />
+                      : <ChevronDown size={14} />
                  )}
                </div>
                <div
@@ -519,19 +514,29 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
              {sortedDownloads.length === 0 ? (
                <div className="downloads-empty-state">
                  <ArrowDownCircle aria-hidden="true" />
-                  <div className="downloads-empty-title">No Downloads</div>
+                  <div className="downloads-empty-title">
+                    {isQueueFilter ? 'Queue is empty' : filter === 'completed' ? 'No Completed Downloads' : 'No Downloads'}
+                  </div>
                  <div className="downloads-empty-description flex items-center justify-center mt-2.5 text-[13px] text-text-muted">
-                    Click <Plus size={15} className="text-accent stroke-[3] mx-1.5" /> button or 
-                    <span className="flex items-center mx-1.5">
-                      <span className="flex items-center justify-center px-1.5 py-0.5 bg-item-hover rounded border border-border-color shadow-sm min-w-[22px] min-h-[22px]">
-                        {isMac ? <Command size={12} strokeWidth={2.5} className="text-text-primary" /> : <span className="text-[10px] font-bold text-text-primary">Ctrl</span>}
-                      </span>
-                      <span className="text-accent font-bold mx-1.5 text-[14px]">+</span>
-                      <span className="flex items-center justify-center px-1.5 py-0.5 bg-item-hover rounded border border-border-color shadow-sm min-w-[22px] min-h-[22px]">
-                        <span className="text-[11px] font-bold text-text-primary">V</span>
-                      </span>
-                    </span>
-                    to add downloads
+                    {isQueueFilter ? (
+                      'Add downloads to this queue from an item menu or the Add window.'
+                    ) : filter === 'completed' ? (
+                      'Completed downloads will appear here.'
+                    ) : (
+                      <>
+                        Click <Plus size={15} className="text-accent stroke-[3] mx-1.5" /> button or
+                        <span className="flex items-center mx-1.5">
+                          <span className="flex items-center justify-center px-1.5 py-0.5 bg-item-hover rounded border border-border-color shadow-sm min-w-[22px] min-h-[22px]">
+                            {isMac ? <Command size={12} strokeWidth={2.5} className="text-text-primary" /> : <span className="text-[10px] font-bold text-text-primary">Ctrl</span>}
+                          </span>
+                          <span className="text-accent font-bold mx-1.5 text-[14px]">+</span>
+                          <span className="flex items-center justify-center px-1.5 py-0.5 bg-item-hover rounded border border-border-color shadow-sm min-w-[22px] min-h-[22px]">
+                            <span className="text-[11px] font-bold text-text-primary">V</span>
+                          </span>
+                        </span>
+                        to add downloads
+                      </>
+                    )}
                  </div>
                </div>
              ) : (
@@ -576,27 +581,17 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
            
            const itemsToResume = selectedDownloads.filter(d => canStartDownload(d.status));
            const itemsToPause = selectedDownloads.filter(d => canPauseDownload(d.status));
+            const itemsToQueue = selectedDownloads.filter(d => d.status !== 'completed');

            return (
            <>
              {/* Multi-Select Context Menu */}
              {itemsToResume.length > 0 && (
              <button
-                onClick={() => {
-                  setContextMenu(null);
-                  if (itemsToResume.length > 0) {
-                    const activeQueueIds = Array.from(new Set(itemsToResume.map(i => i.queueId).filter(Boolean)));
-                    // We can use assignToQueue for bulk resume to the same queue
-                    if (activeQueueIds.length === 1 && activeQueueIds[0]) {
-                      void assignToQueue(itemsToResume.map(i => i.id), activeQueueIds[0]).catch(error => {
-                        showInteractionError('Could not bulk resume downloads', error);
-                      });
-                    } else {
-                      // Fallback for missing queue or multiple queues
-                      itemsToResume.forEach(handleResume);
-                    }
-                  }
-                }}
+              onClick={() => {
+                setContextMenu(null);
+                void resumeItemsSequentially(itemsToResume);
+              }}
                className="w-full text-left px-3 py-2 hover:bg-item-hover transition-colors"
              >
                Start/Resume
@@ -630,24 +625,26 @@ export const DownloadTable: React.FC<DownloadTableProps> = ({ filter }) => {
                <div className="h-[1px] bg-border-modal/60 my-1.5 mx-2"></div>
              )}

-              <div className="group relative">
-                <button className="w-full text-left px-3 py-2 hover:bg-item-hover transition-colors flex justify-between items-center">
-                  Add to Queue
-                  <ChevronRight size={14} />
-                </button>
-                <div className="absolute left-full top-0 hidden group-hover:block ml-1 min-w-[150px] bg-bg-modal border border-border-modal rounded-lg shadow-lg py-1.5 z-50">
-                  {queues.map(q => (
-                    <button key={q.id} onClick={() => {
-                      setContextMenu(null);
-                      void assignToQueue(Array.from(selectedIds), q.id).catch(error => {
-                        showInteractionError('Could not move downloads to queue', error);
-                      });
-                    }} className="w-full text-left px-3 py-2 hover:bg-item-hover transition-colors text-[12px]">
-                      {q.name}
-                    </button>
-                  ))}
+              {itemsToQueue.length > 0 && (
+                <div className="group relative">
+                  <button className="w-full text-left px-3 py-2 hover:bg-item-hover transition-colors flex justify-between items-center">
+                    Add to Queue
+                    <ChevronRight size={14} />
+                  </button>
+                  <div className="absolute left-full top-0 hidden group-hover:block ml-1 min-w-[150px] bg-bg-modal border border-border-modal rounded-lg shadow-lg py-1.5 z-50">
+                    {queues.map(q => (
+                      <button key={q.id} onClick={() => {
+                        setContextMenu(null);
+                        void assignToQueue(itemsToQueue.map(item => item.id), q.id).catch(error => {
+                          showInteractionError('Could not move downloads to queue', error);
+                        });
+                      }} className="w-full text-left px-3 py-2 hover:bg-item-hover transition-colors text-[12px]">
+                        {q.name}
+                      </button>
+                    ))}
+                  </div>
                </div>
-              </div>
+              )}

              <div className="h-[1px] bg-border-modal/60 my-1.5 mx-2"></div>

@@ -10,6 +10,7 @@ import { useDownloadStore, DownloadCategory, Queue } from '../store/useDownloadS
 import { ActiveView, useSettingsStore } from '../store/useSettingsStore';
 import { WindowDragRegion } from './WindowDragRegion';
 import { useToast } from '../contexts/ToastContext';
+import { isTransferActiveStatus } from '../utils/downloads';

 export type SidebarFilter = 'all' | 'active' | 'completed' | 'unfinished' | DownloadCategory | 'settings' | string;

@@ -100,7 +101,7 @@ export const Sidebar: React.FC<SidebarProps> = (props) => {
    }
    switch (filter) {
      case 'all': return downloads.length;
-      case 'active': return downloads.filter(d => d.status === 'downloading').length;
+      case 'active': return downloads.filter(d => isTransferActiveStatus(d.status)).length;
      case 'completed': return downloads.filter(d => d.status === 'completed').length;
      case 'unfinished': return downloads.filter(d => d.status !== 'completed').length;
      default: return downloads.filter(d => d.category === filter as DownloadCategory).length;
@@ -330,14 +331,34 @@ export const Sidebar: React.FC<SidebarProps> = (props) => {
        >
          <button
            className="w-full text-left px-3 py-1.5 flex items-center hover:bg-item-hover"
-            onClick={() => { startQueue(contextMenu.id); setContextMenu(null); }}
+            onClick={() => {
+              const queueId = contextMenu.id;
+              setContextMenu(null);
+              void startQueue(queueId).catch(error => {
+                addToast({
+                  message: `Could not start queue: ${String(error)}`,
+                  variant: 'error',
+                  isActionable: true
+                });
+              });
+            }}
          >
            <Play size={14} className="mr-2 text-text-secondary" />
            Start Queue
          </button>
          <button
            className="w-full text-left px-3 py-1.5 flex items-center hover:bg-item-hover"
-            onClick={() => { pauseQueue(contextMenu.id); setContextMenu(null); }}
+            onClick={() => {
+              const queueId = contextMenu.id;
+              setContextMenu(null);
+              void pauseQueue(queueId).catch(error => {
+                addToast({
+                  message: `Could not pause queue: ${String(error)}`,
+                  variant: 'error',
+                  isActionable: true
+                });
+              });
+            }}
          >
            <Pause size={14} className="mr-2 text-text-secondary" />
            Pause Queue
@@ -82,6 +82,7 @@ type CommandMap = {
  cancel_enqueue_generation: { args: { id: string; generation: string }; result: void };
  enqueue_many: { args: { items: EnqueueItem[] }; result: import('./bindings/EnqueueResult').EnqueueResult[] };
  move_in_queue: { args: { id: string; queueId: string; direction: 'up' | 'down' }; result: string[] };
+  move_many_in_queue: { args: { ids: string[]; queueId: string; direction: 'up' | 'down' }; result: string[] };
  remove_from_queue: { args: { id: string }; result: boolean };
 };

@@ -1,5 +1,6 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 import { initDownloadListener, useDownloadProgressStore } from './downloadStore';
+import { useDownloadStore } from './useDownloadStore';
 import * as ipc from '../ipc';

 vi.mock('../ipc', () => ({
@@ -45,4 +46,41 @@ describe('useDownloadProgressStore', () => {
    releaseSecond();
    expect(unlisten).toHaveBeenCalledTimes(3);
  });
+
+  it('ignores late progress and opposite terminal events from an older lifecycle', async () => {
+    const handlers: Record<string, (event: any) => void> = {};
+    vi.mocked(ipc.listenEvent).mockImplementation((event, handler) => {
+      handlers[event] = handler as (event: any) => void;
+      return Promise.resolve(vi.fn());
+    });
+    useDownloadStore.setState({
+      downloads: [{
+        id: 'terminal',
+        url: 'https://example.com/file',
+        fileName: 'file.bin',
+        status: 'completed',
+        category: 'Other',
+        dateAdded: ''
+      }]
+    });
+
+    const release = await initDownloadListener();
+    handlers['download-progress']({ payload: {
+      id: 'terminal',
+      fraction: 0.1,
+      speed: '1 MB/s',
+      eta: '10s',
+      size: '1 MB',
+      size_is_final: false
+    } });
+    handlers['download-state']({ payload: {
+      id: 'terminal',
+      status: 'failed',
+      error: 'stale failure'
+    } });
+
+    expect(useDownloadProgressStore.getState().progressMap).toEqual({});
+    expect(useDownloadStore.getState().downloads[0].status).toBe('completed');
+    release();
+  });
 });
@@ -52,10 +52,15 @@ const startDownloadListeners = async () => {
  const registrations = await Promise.allSettled([
    listen('download-progress', (event) => {
      const payload = event.payload;
-      useDownloadProgressStore.getState().updateDownloadProgress(payload.id, payload);
-
      const mainStore = useDownloadStore.getState();
      const current = mainStore.downloads.find(d => d.id === payload.id);
+      // A sidecar can flush one last progress chunk after a pause, failure,
+      // or completion event. Do not let that stale chunk repopulate the live
+      // progress map or overwrite a later lifecycle's first frame.
+      if (current && ['completed', 'failed', 'paused'].includes(current.status)) {
+        return;
+      }
+      useDownloadProgressStore.getState().updateDownloadProgress(payload.id, payload);
      if (current) {
        const shouldUpdateSize = Boolean(payload.size && (!current.isMedia || payload.size_is_final));
        const updates: Partial<DownloadItem> = {};
@@ -81,7 +86,7 @@ const startDownloadListeners = async () => {

        // Prevent race condition: don't transition backwards from terminal state
        if ((current.status === 'completed' || current.status === 'failed') &&
-            (status !== 'completed' && status !== 'failed')) {
+            status !== current.status) {
          return;
        }

@@ -248,8 +248,15 @@ describe('useDownloadStore', () => {
      );
    });

-    await useDownloadStore.getState().removeDownload('late');
+    const remove = useDownloadStore.getState().removeDownload('late');
+    await vi.waitFor(() => {
+      expect(ipc.invokeCommand).toHaveBeenCalledWith(
+        'cancel_enqueue_generation',
+        expect.objectContaining({ id: 'late' })
+      );
+    });
    resolveEnqueue({ id: 'late', filename: 'late.bin' });
+    await remove;

    await expect(start).resolves.toEqual([]);
    expect(useDownloadStore.getState().downloads).toEqual([]);
@@ -688,6 +695,134 @@ describe('useDownloadStore', () => {
    expect(useDownloadStore.getState().downloads.find(item => item.id === 'done')?.queueId).toBe('old');
  });

+  it('does not reassign an item that completes while queue assignment is awaiting cancellation', async () => {
+    useDownloadStore.setState({
+      downloads: [
+        { id: 'race-ready', status: 'ready', queueId: 'old' },
+        { id: 'race-done', status: 'completed', queueId: 'old' }
+      ] as any[]
+    });
+
+    let resolveCancellation!: () => void;
+    const cancellation = new Promise<void>(resolve => {
+      resolveCancellation = resolve;
+    });
+    vi.mocked(ipc.invokeCommand).mockImplementation((command: string) => {
+      if (command === 'cancel_enqueue_generation') return cancellation as never;
+      return Promise.resolve(undefined) as never;
+    });
+
+    const assignment = useDownloadStore.getState().assignToQueue(['race-ready', 'race-done'], 'new');
+    await vi.waitFor(() => {
+      expect(ipc.invokeCommand).toHaveBeenCalledWith(
+        'cancel_enqueue_generation',
+        expect.objectContaining({ id: 'race-ready' })
+      );
+    });
+    useDownloadStore.getState().updateDownload('race-ready', { status: 'completed' });
+    resolveCancellation();
+    await assignment;
+
+    expect(useDownloadStore.getState().downloads.find(item => item.id === 'race-ready')).toMatchObject({
+      status: 'completed',
+      queueId: 'old'
+    });
+  });
+
+  it('cancels the rest of a queue start when pause is requested during dispatch', async () => {
+    useDownloadStore.setState({
+      downloads: [
+        { id: 'queue-first', url: 'http://test/first', fileName: 'first', destination: '/tmp', status: 'ready', category: 'Other', dateAdded: '', queueId: 'race-queue', queuePosition: 0 },
+        { id: 'queue-second', url: 'http://test/second', fileName: 'second', destination: '/tmp', status: 'ready', category: 'Other', dateAdded: '', queueId: 'race-queue', queuePosition: 1 }
+      ] as any[]
+    });
+
+    let resolveEnqueue!: (value: { id: string; filename: string }) => void;
+    const enqueue = new Promise<{ id: string; filename: string }>(resolve => {
+      resolveEnqueue = resolve;
+    });
+    vi.mocked(ipc.invokeCommand).mockImplementation((command: string) => {
+      if (command === 'enqueue_download') return enqueue as never;
+      return Promise.resolve(undefined) as never;
+    });
+
+    const start = useDownloadStore.getState().startQueue('race-queue');
+    await vi.waitFor(() => {
+      expect(ipc.invokeCommand).toHaveBeenCalledWith(
+        'enqueue_download',
+        expect.objectContaining({ item: expect.objectContaining({ id: 'queue-first' }) })
+      );
+    });
+    const pause = useDownloadStore.getState().pauseQueue('race-queue');
+    resolveEnqueue({ id: 'queue-first', filename: 'first' });
+
+    await expect(pause).resolves.toBe(1);
+    await expect(start).resolves.toEqual([]);
+    expect(
+      vi.mocked(ipc.invokeCommand).mock.calls.filter(([command, args]) =>
+        command === 'enqueue_download' && (args as any)?.item?.id === 'queue-second'
+      )
+    ).toHaveLength(0);
+  });
+
+  it('uses one atomic backend move and keeps queue positions unique around active transfers', async () => {
+    useDownloadStore.setState({
+      downloads: [
+        { id: 'active', status: 'downloading', queueId: 'move-queue', queuePosition: 0 },
+        { id: 'one', status: 'queued', queueId: 'move-queue', queuePosition: 1 },
+        { id: 'two', status: 'queued', queueId: 'move-queue', queuePosition: 2 },
+        { id: 'three', status: 'queued', queueId: 'move-queue', queuePosition: 3 }
+      ] as any[],
+      backendRegisteredIds: new Set(['three']),
+      pendingOrder: ['one', 'two', 'three']
+    });
+    vi.mocked(ipc.invokeCommand).mockImplementation(async (command: string) => {
+      if (command === 'move_many_in_queue') return ['one', 'three', 'two'];
+      if (command === 'get_pending_order') return ['one', 'three', 'two'];
+      return undefined;
+    });
+
+    await useDownloadStore.getState().moveInQueue('three', 'up');
+
+    expect(vi.mocked(ipc.invokeCommand)).toHaveBeenCalledWith('move_many_in_queue', {
+      ids: ['three'],
+      queueId: 'move-queue',
+      direction: 'up'
+    });
+    expect(vi.mocked(ipc.invokeCommand)).not.toHaveBeenCalledWith('move_in_queue', expect.anything());
+    const positions = useDownloadStore.getState().downloads
+      .filter(item => item.queueId === 'move-queue')
+      .map(item => item.queuePosition);
+    expect(new Set(positions).size).toBe(4);
+  });
+
+  it('detaches a registered queued item through the backend before reassigning it', async () => {
+    useDownloadStore.setState({
+      downloads: [{
+        id: 'registered-queued',
+        url: 'https://example.com/file',
+        fileName: 'file.bin',
+        status: 'queued',
+        category: 'Other',
+        dateAdded: '',
+        queueId: 'old',
+        queuePosition: 0
+      }],
+      backendRegisteredIds: new Set(['registered-queued']),
+      pendingOrder: ['registered-queued']
+    });
+    vi.mocked(ipc.invokeCommand).mockResolvedValue(undefined as never);
+
+    await useDownloadStore.getState().assignToQueue(['registered-queued'], 'new');
+
+    expect(vi.mocked(ipc.invokeCommand)).toHaveBeenCalledWith(
+      'detach_download_for_reconfigure',
+      { id: 'registered-queued' }
+    );
+    expect(useDownloadStore.getState().pendingOrder).not.toContain('registered-queued');
+    expect(useDownloadStore.getState().downloads[0].status).toBe('staged');
+  });
+
  it('disables scheduler when its last selected queue is deleted', async () => {
    const originalSettings = useSettingsStore.getState();
    const setScheduler = vi.fn();
@@ -7,7 +7,7 @@ import type { DownloadStatus } from '../bindings/DownloadStatus';
 import type { ExtensionDownload } from '../bindings/ExtensionDownload';
 import type { Queue } from '../bindings/Queue';
 import { useSettingsStore } from './useSettingsStore';
-import { categoryForFileName, isActiveDownloadStatus, normalizeSpeedLimitForBackend, redactDownloadForPersistence } from '../utils/downloads';
+import { categoryForFileName, isActiveDownloadStatus, isTransferActiveStatus, normalizeSpeedLimitForBackend, redactDownloadForPersistence } from '../utils/downloads';
 import {
  resolveCategoryDestination
 } from '../utils/downloadLocations';
@@ -17,6 +17,56 @@ export type { DownloadCategory } from '../utils/downloads';

 const backendDispatchPromises = new Map<string, Promise<boolean>>();
 const downloadLifecycleGenerations = new Map<string, bigint>();
+const queueReorderPromises = new Map<string, Promise<void>>();
+const queueStartPromises = new Map<string, Promise<string[]>>();
+const queueControlGenerations = new Map<string, number>();
+
+const currentQueueControlGeneration = (queueId: string): number =>
+  queueControlGenerations.get(queueId) ?? 0;
+
+const advanceQueueControlGeneration = (queueId: string): number => {
+  const nextGeneration = currentQueueControlGeneration(queueId) + 1;
+  queueControlGenerations.set(queueId, nextGeneration);
+  return nextGeneration;
+};
+
+const isCurrentQueueControlGeneration = (queueId: string, generation: number): boolean =>
+  currentQueueControlGeneration(queueId) === generation;
+
+const queuePositionComparator = (left: DownloadItem, right: DownloadItem): number =>
+  (left.queuePosition ?? Number.MAX_SAFE_INTEGER) - (right.queuePosition ?? Number.MAX_SAFE_INTEGER) ||
+  left.id.localeCompare(right.id);
+
+const queueItemsForReordering = (downloads: DownloadItem[], queueId: string): DownloadItem[] =>
+  downloads
+    .filter(download =>
+      (download.queueId || MAIN_QUEUE_ID) === queueId &&
+      download.status !== 'completed' &&
+      !(isActiveDownloadStatus(download.status) && download.status !== 'queued')
+    )
+    .sort(queuePositionComparator);
+
+const activeQueueItems = (downloads: DownloadItem[], queueId: string): DownloadItem[] =>
+  downloads
+    .filter(download =>
+      (download.queueId || MAIN_QUEUE_ID) === queueId &&
+      download.status !== 'completed' &&
+      isActiveDownloadStatus(download.status) &&
+      download.status !== 'queued'
+    )
+    .sort(queuePositionComparator);
+
+const applyQueueOrder = (
+  downloads: DownloadItem[],
+  queueId: string,
+  pendingItems: DownloadItem[]
+): DownloadItem[] => {
+  const orderedItems = [...activeQueueItems(downloads, queueId), ...pendingItems];
+  const positions = new Map(orderedItems.map((download, position) => [download.id, position]));
+  return downloads.map(download => positions.has(download.id)
+    ? { ...download, queuePosition: positions.get(download.id) }
+    : download);
+};

 const advanceDownloadLifecycle = (id: string): bigint => {
  const nextGeneration = (downloadLifecycleGenerations.get(id) ?? 0n) + 1n;
@@ -290,7 +340,7 @@ export const getSiteLogin = (url: string, settings: ReturnType<typeof useSetting

 const syncSystemIntegrations = () => {
  const settings = useSettingsStore.getState();
-  const activeCount = useDownloadStore.getState().downloads.filter(d => d.status === 'downloading').length;
+  const activeCount = useDownloadStore.getState().downloads.filter(d => isTransferActiveStatus(d.status)).length;
  invoke('update_dock_badge', { count: settings.showDockBadge ? activeCount : 0 }).catch(() => {});
 };

@@ -395,73 +445,87 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({
  queues: [{ id: MAIN_QUEUE_ID, name: 'Main Queue', isMain: true }],
  pendingOrder: [],
  setPendingOrder: (order) => set({ pendingOrder: order }),
-  moveInQueue: async (idOrIds, direction) => {
+  moveInQueue: (idOrIds, direction) => {
    const ids = Array.isArray(idOrIds) ? idOrIds : [idOrIds];
-    if (ids.length === 0) return;
-    
-    // Assume all items belong to the same queue as the first item
-    const firstItem = get().downloads.find(d => d.id === ids[0]);
-    if (!firstItem) return;
+    if (ids.length === 0) return Promise.resolve();
+
+    // Queue moves must be serialized per queue. Otherwise two optimistic
+    // moves can calculate from the same order and the last RPC silently wins.
+    const firstItem = get().downloads.find(download => ids.includes(download.id));
+    if (!firstItem) return Promise.resolve();
    const queueId = firstItem.queueId || MAIN_QUEUE_ID;
-    
-    const queueItems = get().downloads
-      .filter(download => 
-        (download.queueId || MAIN_QUEUE_ID) === queueId && 
-        download.status !== 'completed' &&
-        !(isActiveDownloadStatus(download.status) && download.status !== 'queued')
-      )
-      .sort((left, right) => (left.queuePosition ?? 0) - (right.queuePosition ?? 0));
-    
-    const selectedItems = queueItems.filter(item => ids.includes(item.id));
-    if (selectedItems.length === 0) return;
-    
-    const unselectedItems = queueItems.filter(item => !ids.includes(item.id));
-    const selectedIndices = selectedItems.map(item => queueItems.findIndex(d => d.id === item.id));
-    
-    let insertIndex = 0;
-    if (direction === 'up') {
-      const firstSelectedIndex = Math.min(...selectedIndices);
-      insertIndex = Math.max(0, firstSelectedIndex - 1);
-    } else {
-      const lastSelectedIndex = Math.max(...selectedIndices);
-      insertIndex = Math.min(unselectedItems.length, lastSelectedIndex - selectedItems.length + 2);
-    }
-    
-    const reordered = [
-      ...unselectedItems.slice(0, insertIndex),
-      ...selectedItems,
-      ...unselectedItems.slice(insertIndex)
-    ];
-    
-    const positions = new Map(reordered.map((download, position) => [download.id, position]));
-    const previousDownloads = get().downloads;
-    set(state => ({
-      downloads: state.downloads.map(download => positions.has(download.id)
-        ? { ...download, queuePosition: positions.get(download.id) }
-        : download)
-    }));
+    const previousOperation = queueReorderPromises.get(queueId) ?? Promise.resolve();
+    const operation = previousOperation.catch(() => undefined).then(async () => {
+      const allDownloads = get().downloads;
+      const queueItems = queueItemsForReordering(allDownloads, queueId);

-    const registeredIdsToMove = selectedItems
-      .filter(item => get().backendRegisteredIds.has(item.id))
-      .map(item => item.id);
-      
-    if (registeredIdsToMove.length === 0) return;
-    
-    // For backend sync, we must call move_in_queue in the correct order to maintain the block
-    const idsToMove = direction === 'up' ? registeredIdsToMove : [...registeredIdsToMove].reverse();
+      const selectedItems = queueItems.filter(item => ids.includes(item.id));
+      if (selectedItems.length === 0) return;

-    try {
-      let order: string[] = [];
-      for (const id of idsToMove) {
-        order = (await invoke('move_in_queue', { id, queueId, direction })) as string[];
+      const previousPositions = new Map([
+        ...activeQueueItems(allDownloads, queueId),
+        ...queueItems
+      ].map(item => [item.id, item.queuePosition]));
+      const unselectedItems = queueItems.filter(item => !ids.includes(item.id));
+      const selectedIndices = selectedItems.map(item => queueItems.findIndex(d => d.id === item.id));
+
+      let insertIndex = 0;
+      if (direction === 'up') {
+        const firstSelectedIndex = Math.min(...selectedIndices);
+        insertIndex = Math.max(0, firstSelectedIndex - 1);
+      } else {
+        const lastSelectedIndex = Math.max(...selectedIndices);
+        insertIndex = Math.min(unselectedItems.length, lastSelectedIndex - selectedItems.length + 2);
      }
-      if (order.length > 0) {
-        set({ pendingOrder: order });
+
+      const reordered = [
+        ...unselectedItems.slice(0, insertIndex),
+        ...selectedItems,
+        ...unselectedItems.slice(insertIndex)
+      ];
+      set(state => ({ downloads: applyQueueOrder(state.downloads, queueId, reordered) }));
+
+      const registeredIdsToMove = selectedItems
+        .filter(item => get().backendRegisteredIds.has(item.id))
+        .map(item => item.id);
+      if (registeredIdsToMove.length === 0) return;
+
+      try {
+        const order = await invoke('move_many_in_queue', {
+          ids: registeredIdsToMove,
+          queueId,
+          direction
+        }) as string[];
+        if (Array.isArray(order)) {
+          const globalOrder = await invoke('get_pending_order', { queueId: null })
+            .catch(() => null) as string[] | null;
+          set(state => ({
+            pendingOrder: Array.isArray(globalOrder)
+              ? globalOrder
+              : [
+                  ...state.pendingOrder.filter(id => !order.includes(id)),
+                  ...order
+                ]
+          }));
+        }
+      } catch (error) {
+        console.error("Failed to move in queue backend:", error);
+        // The backend operation is atomic. Restore only queue positions so a
+        // progress/state event received while the RPC was in flight survives.
+        set(state => ({
+          downloads: state.downloads.map(download => previousPositions.has(download.id)
+            ? { ...download, queuePosition: previousPositions.get(download.id) }
+            : download)
+        }));
      }
-    } catch (e) {
-      console.error("Failed to move in queue backend:", e);
-      set({ downloads: previousDownloads });
-    }
+    });
+    const trackedOperation = operation.finally(() => {
+      if (queueReorderPromises.get(queueId) === trackedOperation) {
+        queueReorderPromises.delete(queueId);
+      }
+    });
+    queueReorderPromises.set(queueId, trackedOperation);
+    return trackedOperation;
  },
  removeFromQueue: async (id) => {
    try {
@@ -643,8 +707,9 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({

    if (item.status === 'queued') {
      if (isRegistered) {
-        await invoke('remove_from_queue', { id });
+        await invoke('detach_download_for_reconfigure', { id });
        state.unregisterBackendIds([id]);
+        set(current => ({ pendingOrder: current.pendingOrder.filter(value => value !== id) }));
      }
      state.updateDownload(id, updates);
      if (isRegistered || wasDispatching) {
@@ -692,7 +757,10 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({
    }
  },
  removeDownload: async (id, deleteFile = false, preserveResumable = false) => {
-    await invalidateDispatch(id);
+    const { pendingDispatch } = await invalidateDispatch(id);
+    if (pendingDispatch) {
+      await pendingDispatch;
+    }
    const item = get().downloads.find(d => d.id === id);

    if (item) {
@@ -820,56 +888,89 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({
      return false;
    }
  },
-  startQueue: async (queueId) => {
-    const runnable = get().downloads
-      .filter(item => item.queueId === queueId && (item.status === 'queued' || canStartDownload(item.status)))
-      .sort((left, right) => (left.queuePosition ?? 0) - (right.queuePosition ?? 0));
+  startQueue: (queueId) => {
+    const requestedGeneration = currentQueueControlGeneration(queueId);
+    const previousOperation = queueStartPromises.get(queueId) ?? Promise.resolve([]);
+    const operation = previousOperation.catch(() => []).then(async () => {
+      const runnable = get().downloads
+        .filter(item => item.queueId === queueId && (item.status === 'queued' || canStartDownload(item.status)))
+        .sort(queuePositionComparator);

-    if (runnable.length === 0) return [];
+      if (runnable.length === 0 || !isCurrentQueueControlGeneration(queueId, requestedGeneration)) return [];

-    const acceptedIds: string[] = [];
-    for (const item of runnable) {
-      const backendRegistered = get().backendRegisteredIds.has(item.id);
-      const backendPending = get().pendingOrder.includes(item.id);
+      const acceptedIds: string[] = [];
+      for (const item of runnable) {
+        if (!isCurrentQueueControlGeneration(queueId, requestedGeneration)) break;

-      if (item.status === 'queued' && backendRegistered && !backendPending) {
-        if (await get().resumeDownload(item.id)) {
+        const currentItem = get().downloads.find(download => download.id === item.id);
+        if (!currentItem || currentItem.status === 'completed') continue;
+        const backendRegistered = get().backendRegisteredIds.has(item.id);
+        const backendPending = get().pendingOrder.includes(item.id);
+
+        if (currentItem.status === 'queued' && backendRegistered && !backendPending) {
+          if (await get().resumeDownload(item.id)) {
+            acceptedIds.push(item.id);
+          }
+          continue;
+        }
+
+        if (
+          currentItem.status === 'ready' ||
+          currentItem.status === 'staged' ||
+          currentItem.status === 'failed' ||
+          !currentItem.hasBeenDispatched ||
+          !backendRegistered
+        ) {
+          if (await dispatchItem(item.id)) {
+            if (!isCurrentQueueControlGeneration(queueId, requestedGeneration)) {
+              const afterDispatch = get().downloads.find(download => download.id === item.id);
+              if (
+                backendDispatchPromises.has(item.id) ||
+                get().backendRegisteredIds.has(item.id) ||
+                (afterDispatch && canPauseDownload(afterDispatch.status))
+              ) {
+                await get().pauseDownload(item.id);
+              }
+              continue;
+            }
+            const current = get().downloads.find(download => download.id === item.id);
+            get().updateDownload(item.id, {
+              hasBeenDispatched: true,
+              ...(current?.status === item.status ? { status: 'queued' as const } : {})
+            });
+            acceptedIds.push(item.id);
+          }
+        } else if (currentItem.status === 'paused' || currentItem.status === 'queued') {
+          // If it's queued but already dispatched, it might be waiting.
+          // If it's paused, we resume it.
+          if (currentItem.status === 'paused') {
+            if (!await get().resumeDownload(item.id)) continue;
+          }
          acceptedIds.push(item.id);
        }
-        continue;
      }

-      if (
-        item.status === 'ready' ||
-        item.status === 'staged' ||
-        item.status === 'failed' ||
-        !item.hasBeenDispatched ||
-        !backendRegistered
-      ) {
-        if (await dispatchItem(item.id)) {
-          const current = get().downloads.find(download => download.id === item.id);
-          get().updateDownload(item.id, {
-            hasBeenDispatched: true,
-            ...(current?.status === item.status ? { status: 'queued' as const } : {})
-          });
-          acceptedIds.push(item.id);
-        }
-      } else if (item.status === 'paused' || item.status === 'queued') {
-        // If it's queued but already dispatched, it might be waiting. 
-        // If it's paused, we resume it.
-        if (item.status === 'paused') {
-          if (!await get().resumeDownload(item.id)) continue;
-        }
-        acceptedIds.push(item.id);
+      info(`Queue ${queueId} started, ${acceptedIds.length} items dispatched/resumed`);
+      return acceptedIds;
+    });
+    const trackedOperation = operation.finally(() => {
+      if (queueStartPromises.get(queueId) === trackedOperation) {
+        queueStartPromises.delete(queueId);
      }
-    }
-
-    info(`Queue ${queueId} started, ${acceptedIds.length} items dispatched/resumed`);
-    return acceptedIds;
+    });
+    queueStartPromises.set(queueId, trackedOperation);
+    return trackedOperation;
  },
  pauseQueue: async (queueId) => {
+    // Invalidate queued starts before taking the snapshot. This prevents a
+    // start loop that is waiting on metadata/IPC from dispatching later rows
+    // after the user has already requested Pause Queue.
+    advanceQueueControlGeneration(queueId);
    const activeIds = get().downloads
-      .filter(item => item.queueId === queueId && canPauseDownload(item.status))
+      .filter(item =>
+        item.queueId === queueId &&
+        (canPauseDownload(item.status) || backendDispatchPromises.has(item.id))
+      )
      .map(item => item.id);

    if (activeIds.length === 0) return 0;
@@ -899,8 +1000,14 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({
    return results.reduce((total, ids) => total + ids.length, 0);
  },
  pauseAll: async () => {
+    const queueIds = new Set(
+      get().downloads.map(item => item.queueId || MAIN_QUEUE_ID)
+    );
+    for (const queueId of queueIds) {
+      advanceQueueControlGeneration(queueId);
+    }
    const activeIds = get().downloads
-      .filter(item => canPauseDownload(item.status))
+      .filter(item => canPauseDownload(item.status) || backendDispatchPromises.has(item.id))
      .map(item => item.id);
    if (activeIds.length === 0) return 0;

@@ -917,35 +1024,33 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({
      throw new Error(`Pause ${locked.fileName} before moving it to another queue.`);
    }

-    await Promise.all(
-      selected
-        .filter(item => item.status !== 'completed')
-        .map(item => invalidateAndWaitForDispatch(item.id))
-    );
+    const movableSelected = selected.filter(item => item.status !== 'completed');
+    const movableIds = new Set(movableSelected.map(item => item.id));
+    await Promise.all(movableSelected.map(item => invalidateAndWaitForDispatch(item.id)));

-    for (const item of get().downloads.filter(item => selectedIds.has(item.id))) {
+    for (const item of get().downloads.filter(item => movableIds.has(item.id))) {
      if (!get().backendRegisteredIds.has(item.id)) continue;
-      if (item.status === 'queued') {
-        await invoke('remove_from_queue', { id: item.id });
-      } else if (item.status === 'paused') {
-        await invoke('detach_download_for_reconfigure', { id: item.id });
-      }
+      // The UI can still say queued while a dispatch has already reached
+      // Aria2/media. Detach through the backend lifecycle owner for every
+      // registered item; remove_from_queue only handles the pending list.
+      await invoke('detach_download_for_reconfigure', { id: item.id });
      get().unregisterBackendIds([item.id]);
+      set(state => ({ pendingOrder: state.pendingOrder.filter(value => value !== item.id) }));
    }

    const queueItems = get().downloads.filter(item =>
-      !selectedIds.has(item.id) &&
+      !movableIds.has(item.id) &&
      (item.queueId || MAIN_QUEUE_ID) === queueId
    );
    const maxPos = queueItems.reduce((max, d) => Math.max(max, d.queuePosition ?? 0), -1);
    const nextPosition = maxPos + 1;
    set(state => ({
      downloads: state.downloads.map(item =>
-        selectedIds.has(item.id) && item.status !== 'completed'
+        movableIds.has(item.id) && item.status !== 'completed'
          ? {
              ...item,
              queueId,
-              queuePosition: nextPosition + selected.findIndex(selectedItem => selectedItem.id === item.id),
+              queuePosition: nextPosition + movableSelected.findIndex(selectedItem => selectedItem.id === item.id),
              status: 'staged' as const,
              hasBeenDispatched: false
            }
@@ -0,0 +1,60 @@
+import { describe, expect, it } from 'vitest';
+import type { DownloadItem } from '../bindings/DownloadItem';
+import {
+  parseDownloadEta,
+  parseDownloadSize,
+  sortDownloads,
+  type DownloadSortConfig
+} from './downloadTableSorting';
+import { redactDownloadForPersistence } from './downloads';
+
+const item = (id: string, overrides: Partial<DownloadItem> = {}): DownloadItem => ({
+  id,
+  url: `https://example.test/${id}`,
+  fileName: id,
+  status: 'queued',
+  category: 'Other',
+  dateAdded: '2026-07-14T00:00:00.000Z',
+  ...overrides
+});
+
+const sortedIds = (downloads: DownloadItem[], config: DownloadSortConfig): string[] =>
+  sortDownloads(downloads, config).map(download => download.id);
+
+describe('download table sorting', () => {
+  it('compares human-readable sizes by bytes instead of their leading number', () => {
+    expect(parseDownloadSize('1 MB')).toBe(1024 ** 2);
+    expect(sortedIds([
+      item('one-mb', { size: '1 MB' }),
+      item('900-kb', { size: '900 KB' }),
+      item('two-mb', { size: '2 MB' })
+    ], { column: 'Size', direction: 'asc' })).toEqual(['900-kb', 'one-mb', 'two-mb']);
+  });
+
+  it('supports clock and unit ETA values and keeps unknown values last', () => {
+    expect(parseDownloadEta('01:02:03')).toBe(3723);
+    expect(parseDownloadEta('2m 5s')).toBe(125);
+    expect(sortedIds([
+      item('unknown', { eta: '-' }),
+      item('long', { eta: '2m' }),
+      item('short', { eta: '10s' })
+    ], { column: 'ETA', direction: 'asc' })).toEqual(['short', 'long', 'unknown']);
+  });
+
+  it('sorts descending on the second click without reverting to an unsorted list', () => {
+    const downloads = [item('b', { fileName: 'Beta' }), item('a', { fileName: 'Alpha' })];
+    expect(sortedIds(downloads, { column: 'File Name', direction: 'asc' })).toEqual(['a', 'b']);
+    expect(sortedIds(downloads, { column: 'File Name', direction: 'desc' })).toEqual(['b', 'a']);
+  });
+
+  it('does not persist volatile progress fields', () => {
+    const persisted = redactDownloadForPersistence(item('volatile', {
+      fraction: 0.75,
+      speed: '1 MB/s',
+      eta: '10s'
+    }));
+    expect(persisted.fraction).toBeUndefined();
+    expect(persisted.speed).toBeUndefined();
+    expect(persisted.eta).toBeUndefined();
+  });
+});
@@ -0,0 +1,110 @@
+import type { DownloadItem } from '../bindings/DownloadItem';
+
+export type DownloadSortColumn = 'File Name' | 'Size' | 'Status' | 'Speed' | 'ETA' | 'Date Added';
+export type DownloadSortDirection = 'asc' | 'desc';
+
+export type DownloadSortConfig = {
+  column: DownloadSortColumn;
+  direction: DownloadSortDirection;
+};
+
+const SIZE_UNITS: Record<string, number> = {
+  B: 1,
+  KB: 1024,
+  KIB: 1024,
+  MB: 1024 ** 2,
+  MIB: 1024 ** 2,
+  GB: 1024 ** 3,
+  GIB: 1024 ** 3,
+  TB: 1024 ** 4,
+  TIB: 1024 ** 4,
+};
+
+const valueOrNull = (value?: string): string | null => {
+  const trimmed = value?.trim();
+  return trimmed && trimmed !== '-' && !/^unknown$/i.test(trimmed) ? trimmed : null;
+};
+
+const parseUnitValue = (value?: string, units = SIZE_UNITS): number | null => {
+  const normalized = valueOrNull(value);
+  if (!normalized) return null;
+  const match = normalized.match(/^([\d.,]+)\s*([KMGT]?I?B)(?:\/s)?$/i);
+  if (!match) {
+    const number = Number(normalized.replace(/,/g, ''));
+    return Number.isFinite(number) ? number : null;
+  }
+
+  const amount = Number(match[1].replace(/,/g, ''));
+  const multiplier = units[match[2].toUpperCase()];
+  return Number.isFinite(amount) && multiplier ? amount * multiplier : null;
+};
+
+export const parseDownloadSize = (value?: string): number | null => parseUnitValue(value);
+
+export const parseDownloadSpeed = (value?: string): number | null =>
+  parseUnitValue(value, SIZE_UNITS);
+
+export const parseDownloadEta = (value?: string): number | null => {
+  const normalized = valueOrNull(value);
+  if (!normalized) return null;
+
+  const clockParts = normalized.split(':').map(part => Number(part));
+  if (clockParts.length >= 2 && clockParts.every(Number.isFinite)) {
+    return clockParts.reduce((total, part, index) => total + part * 60 ** (clockParts.length - index - 1), 0);
+  }
+
+  let seconds = 0;
+  let matched = false;
+  for (const [pattern, multiplier] of [[/(\d+(?:\.\d+)?)h/i, 3600], [/(\d+(?:\.\d+)?)m/i, 60], [/(\d+(?:\.\d+)?)s/i, 1]] as const) {
+    const match = normalized.match(pattern);
+    if (match) {
+      seconds += Number(match[1]) * multiplier;
+      matched = true;
+    }
+  }
+  return matched && Number.isFinite(seconds) ? seconds : null;
+};
+
+const compareValues = (left: string | number | null, right: string | number | null): number => {
+  if (left === null && right === null) return 0;
+  if (left === null) return 1;
+  if (right === null) return -1;
+  if (typeof left === 'number' && typeof right === 'number') return left - right;
+  return String(left).localeCompare(String(right), undefined, { numeric: true, sensitivity: 'base' });
+};
+
+const parseDownloadDate = (value?: string): number | null => {
+  if (!value?.trim()) return null;
+  const timestamp = new Date(value).getTime();
+  return Number.isFinite(timestamp) ? timestamp : null;
+};
+
+export const sortDownloads = (downloads: DownloadItem[], config: DownloadSortConfig): DownloadItem[] => {
+  const sorted = [...downloads].sort((left, right) => {
+    let comparison: number;
+    switch (config.column) {
+      case 'File Name':
+        comparison = compareValues(left.fileName || left.url, right.fileName || right.url);
+        break;
+      case 'Size':
+        comparison = compareValues(parseDownloadSize(left.size), parseDownloadSize(right.size));
+        break;
+      case 'Status':
+        comparison = compareValues(left.status, right.status);
+        break;
+      case 'Speed':
+        comparison = compareValues(parseDownloadSpeed(left.speed), parseDownloadSpeed(right.speed));
+        break;
+      case 'ETA':
+        comparison = compareValues(parseDownloadEta(left.eta), parseDownloadEta(right.eta));
+        break;
+      case 'Date Added':
+        comparison = compareValues(parseDownloadDate(left.dateAdded), parseDownloadDate(right.dateAdded));
+        break;
+    }
+
+    if (comparison === 0) comparison = left.id.localeCompare(right.id);
+    return config.direction === 'asc' ? comparison : -comparison;
+  });
+  return sorted;
+};
@@ -36,6 +36,10 @@ const ACTIVE_DOWNLOAD_STATUSES: ReadonlySet<DownloadStatus> = new Set([
 export const isActiveDownloadStatus = (status: DownloadStatus): boolean =>
  ACTIVE_DOWNLOAD_STATUSES.has(status);

+/** Transfer states that consume a worker/permit. Queued is intentionally excluded. */
+export const isTransferActiveStatus = (status: DownloadStatus): boolean =>
+  status === 'downloading' || status === 'processing' || status === 'retrying';
+
 export const normalizeSpeedLimitForBackend = (value?: string | null): string | null => {
  const trimmed = value?.trim();
  if (!trimmed) return null;
@@ -128,6 +132,7 @@ const DOWNLOAD_SECRET_FIELDS = ['password', 'cookies', 'headers'] as const;
 */
 export const redactDownloadForPersistence = (item: DownloadItem): DownloadItem => {
  const copy: DownloadItem = { ...item };
+  delete copy.fraction;
  delete copy.speed;
  delete copy.eta;
  for (const field of DOWNLOAD_SECRET_FIELDS) {