feat(crawler): live cover + chapter-content observability with realtime page counts

Extends the live dashboard so an operator can see exactly what's being
fetched, in realtime:

- Chapters being crawled now are tracked in the status as `active_chapters`
  (manga title · ch.N) with a live page counter that climbs per stored page
  (set_chapter_pages, pushed via the existing watch→SSE). The dispatcher
  registers each via an RAII ChapterGuard (sync Mutex) that removes the
  entry on completion, panic, or timeout-drop — replacing the old per-worker
  slot model.
- Covers: status now carries the cover being fetched now (`current_cover`,
  set around download_and_store_cover in both the metadata pass and backfill)
  and a `covers_queued` backlog count; CoverBackfill phase gains index/total.
- Two paginated backlog endpoints (fetched on demand, auto-refreshed when the
  live counts change): GET /admin/crawler/active-jobs (which chapters of which
  mangas are queued/running) and GET /admin/crawler/covers (mangas missing a
  cover). repo: list_active_jobs, list_missing_cover_mangas, count_missing_covers.
- dispatch_target now also returns manga title + chapter number.

Frontend: the crawler page replaces the Workers table with an Active-chapters
table (live page bars), adds a current-cover line + covers-queued figure, and
two backlog sections (Queued chapters / Queued covers) with search + Pager,
auto-refetched via $effect on the live counts.

Tests: status guard/page + cover unit tests; repo list/count tests; endpoint
tests; frontend api tests. Version 0.53.1 -> 0.54.0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/Cargo.lock

@@ -1470,7 +1470,7 @@ checksum = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"
 
 [[package]]
 name = "mangalord"
-version = "0.53.1"
+version = "0.54.0"
 dependencies = [
  "anyhow",
  "argon2",

backend/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mangalord"
-version = "0.53.1"
+version = "0.54.0"
 edition = "2021"
 default-run = "mangalord"
 

backend/src/api/admin/crawler.rs

@@ -21,10 +21,10 @@ use uuid::Uuid;
 use crate::app::{AppState, CrawlerControl};
 use crate::auth::extractor::RequireAdmin;
 use crate::crawler::browser_manager::RestartPhase;
-use crate::crawler::status::{LastPass, Phase, WorkerState};
+use crate::crawler::status::{ActiveChapter, CoverTarget, LastPass, Phase};
 use crate::error::{AppError, AppResult};
 use crate::repo;
-use crate::repo::crawler::{DeadJob, RequeueScope};
+use crate::repo::crawler::{ActiveJob, DeadJob, MissingCoverRow, RequeueScope};
 
 /// Backstop recompose interval for the SSE stream. Phase/worker/session
 /// changes push instantly via the status `watch`; this only bounds the
@@ -45,6 +45,8 @@ pub fn routes() -> Router<AppState> {
         )
         .route("/admin/crawler/dead-jobs", get(list_dead_jobs))
         .route("/admin/crawler/dead-jobs/requeue", post(requeue_dead_jobs))
+        .route("/admin/crawler/active-jobs", get(list_active_jobs))
+        .route("/admin/crawler/covers", get(list_covers))
 }
 
 // ---------------------------------------------------------------------------
@@ -71,7 +73,14 @@ struct CrawlerStatusResponse {
     /// `"running"` | `"disabled"`.
     daemon: &'static str,
     phase: Option<Phase>,
-    workers: Vec<WorkerState>,
+    /// Configured chapter-worker count (for "N busy / M workers").
+    worker_count: usize,
+    /// Chapters being crawled right now, with live page counts.
+    active_chapters: Vec<ActiveChapter>,
+    /// The cover being fetched right now, if any.
+    current_cover: Option<CoverTarget>,
+    /// Mangas still queued for a cover fetch.
+    covers_queued: i64,
     last_pass: LastPass,
     session: SessionStatus,
     /// `"healthy"` | `"draining"` | `"restarting"` | `"down"`.
@@ -97,12 +106,16 @@ async fn compose_status(state: &AppState) -> AppResult<CrawlerStatusResponse> {
         running,
         dead,
     };
+    let covers_queued = repo::crawler::count_missing_covers(&state.db).await?;
 
     Ok(match state.crawler.as_ref() {
         None => CrawlerStatusResponse {
             daemon: "disabled",
             phase: None,
-            workers: Vec::new(),
+            worker_count: 0,
+            active_chapters: Vec::new(),
+            current_cover: None,
+            covers_queued,
             last_pass: LastPass::default(),
             session: SessionStatus {
                 expired: false,
@@ -116,7 +129,10 @@ async fn compose_status(state: &AppState) -> AppResult<CrawlerStatusResponse> {
             CrawlerStatusResponse {
                 daemon: "running",
                 phase: Some(snap.phase),
-                workers: snap.workers,
+                worker_count: snap.worker_count,
+                active_chapters: snap.active_chapters,
+                current_cover: snap.current_cover,
+                covers_queued,
                 last_pass: snap.last_pass,
                 session: SessionStatus {
                     expired: c.session.is_expired(),
@@ -420,6 +436,52 @@ fn scope_label(r: &RequeueRequest) -> &'static str {
     }
 }
 
+// ---------------------------------------------------------------------------
+// Queued-chapters + queued-covers backlogs (paginated, fetched on demand)
+// ---------------------------------------------------------------------------
+
+/// Pagination + title-search params shared by the backlog list endpoints.
+#[derive(Debug, Deserialize, Default)]
+struct ListParams {
+    #[serde(default)]
+    search: Option<String>,
+    #[serde(default = "default_limit")]
+    limit: i64,
+    #[serde(default)]
+    offset: i64,
+}
+
+async fn list_active_jobs(
+    State(state): State<AppState>,
+    _admin: RequireAdmin,
+    Query(params): Query<ListParams>,
+) -> AppResult<Json<crate::api::pagination::PagedResponse<ActiveJob>>> {
+    let limit = params.limit.clamp(1, 200);
+    let offset = params.offset.max(0);
+    let search = params.search.filter(|s| !s.trim().is_empty());
+    let (items, total) =
+        repo::crawler::list_active_jobs(&state.db, search.as_deref(), limit, offset).await?;
+    Ok(Json(crate::api::pagination::PagedResponse::with_total(
+        items, limit, offset, total,
+    )))
+}
+
+async fn list_covers(
+    State(state): State<AppState>,
+    _admin: RequireAdmin,
+    Query(params): Query<ListParams>,
+) -> AppResult<Json<crate::api::pagination::PagedResponse<MissingCoverRow>>> {
+    let limit = params.limit.clamp(1, 200);
+    let offset = params.offset.max(0);
+    let search = params.search.filter(|s| !s.trim().is_empty());
+    let (items, total) =
+        repo::crawler::list_missing_cover_mangas(&state.db, search.as_deref(), limit, offset)
+            .await?;
+    Ok(Json(crate::api::pagination::PagedResponse::with_total(
+        items, limit, offset, total,
+    )))
+}
+
 // ---------------------------------------------------------------------------
 
 fn require_crawler(state: &AppState) -> Result<&std::sync::Arc<CrawlerControl>, AppError> {

backend/src/app.rs

@@ -276,6 +276,7 @@ async fn spawn_crawler_daemon(
         transient_failures: Arc::new(AtomicU32::new(0)),
         restart_threshold: cfg.browser_restart_threshold,
         drain_deadline: cfg.job_timeout,
+        status: status.clone(),
         tor: tor.as_ref().map(Arc::clone),
     });
 
@@ -389,10 +390,8 @@ impl MetadataPass for RealMetadataPass {
         // errored — the early-stop walk can complete its work and bail
         // late, and a transient browser failure shouldn't cancel the
         // residual cover backlog. The backfill has its own per-call cap
-        // so a runaway error stream can't monopolise the tick.
-        self.status
-            .set_phase(crate::crawler::status::Phase::CoverBackfill)
-            .await;
+        // so a runaway error stream can't monopolise the tick. It sets the
+        // CoverBackfill{index,total} phase + current_cover per entry.
         match pipeline::backfill_missing_covers(
             &self.browser_manager,
             &self.db,
@@ -402,6 +401,7 @@ impl MetadataPass for RealMetadataPass {
             pipeline::COVER_BACKFILL_DEFAULT_MAX,
             &self.download_allowlist,
             self.max_image_bytes,
+            Some(&self.status),
             self.tor.as_deref(),
         )
         .await
@@ -437,6 +437,9 @@ struct RealChapterDispatcher {
     restart_threshold: u32,
     /// How long a coordinated restart waits for in-flight leases to drain.
     drain_deadline: std::time::Duration,
+    /// Live status surface — the dispatcher registers each chapter it
+    /// crawls (with a realtime page count) here.
+    status: crate::crawler::status::StatusHandle,
     tor: Option<Arc<crate::crawler::tor::TorController>>,
 }
 
@@ -452,10 +455,21 @@ impl ChapterDispatcher for RealChapterDispatcher {
                 let row = repo::chapter::dispatch_target(&self.db, chapter_id)
                     .await
                     .context("look up chapter for dispatch")?;
-                let Some((manga_id, source_url)) = row else {
+                let Some((manga_id, source_url, manga_title, chapter_number)) = row else {
                     // Chapter (or its source row) is gone — ack done.
                     return Ok(SyncOutcome::Skipped);
                 };
+                // Register the chapter as crawling now (live status). The
+                // guard removes it on every exit path — success, panic, or
+                // the worker's outer-timeout drop.
+                let _active = self.status.begin_chapter(crate::crawler::status::ActiveChapter {
+                    manga_id,
+                    manga_title,
+                    chapter_id,
+                    chapter_number,
+                    pages_done: 0,
+                    pages_total: None,
+                });
                 let lease = self.browser_manager.acquire().await?;
                 let result = content::sync_chapter_content(
                     &lease,
@@ -470,6 +484,7 @@ impl ChapterDispatcher for RealChapterDispatcher {
                     &self.download_allowlist,
                     self.max_image_bytes,
                     self.tor.as_deref(),
+                    Some(&self.status),
                 )
                 .await;
                 drop(lease);

backend/src/bin/crawler.rs

@@ -417,6 +417,8 @@ async fn sync_bookmarked_chapter_content(
                     allowlist.as_ref(),
                     max_image_bytes,
                     tor.as_deref(),
+                    // CLI one-shot — no live status surface.
+                    None,
                 )
                 .await;
                 drop(lease);

backend/src/crawler/content.rs

@@ -206,6 +206,10 @@ pub async fn sync_chapter_content(
     allowlist: &DownloadAllowlist,
     max_image_bytes: usize,
     tor: Option<&crate::crawler::tor::TorController>,
+    // Optional live-status sink for the realtime page counter. The daemon
+    // dispatcher passes the shared handle (the chapter has already been
+    // registered via `begin_chapter`); the CLI / admin resync pass `None`.
+    progress: Option<&crate::crawler::status::StatusHandle>,
 ) -> anyhow::Result<SyncOutcome> {
     // Skip if already fetched, unless caller explicitly forces.
     if !force_refetch {
@@ -267,8 +271,13 @@ pub async fn sync_chapter_content(
     // final DB commit) fails — preserving the all-or-nothing guarantee
     // without holding a DB transaction open across the network puts
     // (which matters once `Storage` is backed by S3).
-    let mut written_keys: Vec<String> = Vec::with_capacity(images.len());
-    let mut stored: Vec<StoredPage> = Vec::with_capacity(images.len());
+    let total = images.len();
+    // Publish the now-known page total so the dashboard shows "0/N".
+    if let Some(p) = progress {
+        p.set_chapter_pages(chapter_id, 0, Some(total));
+    }
+    let mut written_keys: Vec<String> = Vec::with_capacity(total);
+    let mut stored: Vec<StoredPage> = Vec::with_capacity(total);
     for img in &images {
         match download_and_store_page(
             storage,
@@ -287,6 +296,10 @@ pub async fn sync_chapter_content(
             Ok(page) => {
                 written_keys.push(page.storage_key.clone());
                 stored.push(page);
+                // Live page counter: push the climbing count to subscribers.
+                if let Some(p) = progress {
+                    p.set_chapter_pages(chapter_id, stored.len(), Some(total));
+                }
             }
             Err(e) => {
                 cleanup_orphans(storage, &written_keys).await;

backend/src/crawler/daemon.rs

@@ -48,7 +48,7 @@ use tokio_util::sync::CancellationToken;
 use crate::crawler::content::SyncOutcome;
 use crate::crawler::jobs::{self, JobPayload, Lease, KIND_SYNC_CHAPTER_CONTENT};
 use crate::crawler::pipeline;
-use crate::crawler::status::{Phase, StatusHandle, WorkerState};
+use crate::crawler::status::{Phase, StatusHandle};
 
 /// Fixed `pg_try_advisory_lock` key. ASCII "MANGALRD" interpreted as a
 /// big-endian i64. Hardcoded so every replica agrees on the lock identity
@@ -396,17 +396,10 @@ impl WorkerContext {
             })
         };
 
-        // Publish what this worker is doing for the live status surface.
-        if let JobPayload::SyncChapterContent { chapter_id, .. } = &lease.payload {
-            self.status
-                .set_worker(
-                    self.id,
-                    WorkerState::Working {
-                        chapter_id: *chapter_id,
-                    },
-                )
-                .await;
-        }
+        // The "currently crawling" chapter (with its live page count) is
+        // registered by the dispatcher itself (RealChapterDispatcher) so it
+        // carries the manga/chapter identity + page progress and is removed
+        // via an RAII guard on every exit path.
 
         // Outer timeout: a dispatch that exceeds `job_timeout` is acked
         // failed (exponential backoff) rather than wedging the worker.
@@ -414,7 +407,6 @@ impl WorkerContext {
             .catch_unwind();
         let outcome = tokio::time::timeout(self.job_timeout, dispatch).await;
         heartbeat.abort();
-        self.status.set_worker(self.id, WorkerState::Idle).await;
 
         let outcome = match outcome {
             Ok(o) => o,

backend/src/crawler/pipeline.rs

@@ -349,7 +349,14 @@ pub async fn run_metadata_pass(
                 || matches!(upsert.status, repo::crawler::UpsertStatus::Updated);
             if needs_cover {
                 if let Some(cover_url) = manga.cover_url.as_deref() {
-                    match download_and_store_cover(
+                    if let Some(s) = status {
+                        s.set_current_cover(Some(crate::crawler::status::CoverTarget {
+                            manga_id: upsert.manga_id,
+                            manga_title: manga.title.clone(),
+                        }))
+                        .await;
+                    }
+                    let cover_result = download_and_store_cover(
                         db,
                         storage,
                         http,
@@ -360,8 +367,11 @@ pub async fn run_metadata_pass(
                         allowlist,
                         max_image_bytes,
                     )
-                    .await
-                    {
+                    .await;
+                    if let Some(s) = status {
+                        s.set_current_cover(None).await;
+                    }
+                    match cover_result {
                         Ok(()) => stats.covers_fetched += 1,
                         Err(e) => tracing::warn!(
                             manga_id = %upsert.manga_id,
@@ -615,6 +625,7 @@ pub async fn backfill_missing_covers(
     max_mangas: usize,
     allowlist: &DownloadAllowlist,
     max_image_bytes: usize,
+    status: Option<&crate::crawler::status::StatusHandle>,
     tor: Option<&crate::crawler::tor::TorController>,
 ) -> anyhow::Result<CoverBackfillStats> {
     let mut stats = CoverBackfillStats::default();
@@ -637,8 +648,13 @@ pub async fn backfill_missing_covers(
     let browser_ref: &chromiumoxide::Browser = &lease;
     let ctx = FetchContext { browser: browser_ref, rate, tor };
 
-    for entry in entries {
+    let total = entries.len();
+    for (index, entry) in entries.into_iter().enumerate() {
         stats.considered += 1;
+        if let Some(s) = status {
+            s.set_phase(crate::crawler::status::Phase::CoverBackfill { index, total })
+                .await;
+        }
         // Metadata-only TargetSource: skip chapter-list parsing so a
         // missing-cover refetch doesn't soft-drop chapters on a partial
         // render. Cover URL alone is what we need.
@@ -648,8 +664,8 @@ pub async fn backfill_missing_covers(
             title: String::new(),
             url: entry.source_url.clone(),
         };
-        let cover_url = match source.fetch_manga(&ctx, &r).await {
-            Ok(manga) => manga.cover_url,
+        let manga = match source.fetch_manga(&ctx, &r).await {
+            Ok(manga) => manga,
             Err(e) => {
                 tracing::warn!(
                     manga_id = %entry.manga_id,
@@ -661,7 +677,7 @@ pub async fn backfill_missing_covers(
                 continue;
             }
         };
-        let Some(cover_url) = cover_url else {
+        let Some(cover_url) = manga.cover_url.clone() else {
             tracing::warn!(
                 manga_id = %entry.manga_id,
                 url = %entry.source_url,
@@ -670,7 +686,14 @@ pub async fn backfill_missing_covers(
             stats.failed += 1;
             continue;
         };
-        match download_and_store_cover(
+        if let Some(s) = status {
+            s.set_current_cover(Some(crate::crawler::status::CoverTarget {
+                manga_id: entry.manga_id,
+                manga_title: manga.title.clone(),
+            }))
+            .await;
+        }
+        let cover_result = download_and_store_cover(
             db,
             storage,
             http,
@@ -681,8 +704,11 @@ pub async fn backfill_missing_covers(
             allowlist,
             max_image_bytes,
         )
-        .await
-        {
+        .await;
+        if let Some(s) = status {
+            s.set_current_cover(None).await;
+        }
+        match cover_result {
             Ok(()) => stats.fetched += 1,
             Err(e) => {
                 tracing::warn!(

backend/src/crawler/resync.rs

@@ -235,7 +235,7 @@ impl ResyncService for RealResyncService {
         let row = repo::chapter::dispatch_target(&self.db, chapter_id)
             .await
             .context("look up chapter_sources for resync")?;
-        let Some((manga_id, source_url)) = row else {
+        let Some((manga_id, source_url, _title, _number)) = row else {
             return Err(ResyncError::NoChapterSource.into());
         };
 
@@ -257,6 +257,8 @@ impl ResyncService for RealResyncService {
             &self.download_allowlist,
             self.max_image_bytes,
             self.tor.as_deref(),
+            // Admin resync isn't a daemon worker slot — no live status.
+            None,
         )
         .await;
         drop(lease);

backend/src/crawler/status.rs

@@ -3,16 +3,17 @@
 //! The metadata pass runs inline in the cron tick (it is not a
 //! `crawler_jobs` row), so without this surface "what is the crawler doing
 //! right now" is unanswerable from the dashboard. The daemon publishes its
-//! current [`Phase`] and per-worker activity into a shared
-//! [`StatusHandle`]; the admin endpoint reads a [`CrawlerStatus`] snapshot
-//! and composes it with DB-derived queue counts + the session/browser
-//! flags.
+//! current [`Phase`], the chapters being crawled right now (with a live
+//! page count), and the cover being fetched into a shared [`StatusHandle`];
+//! the admin endpoint reads a [`CrawlerStatus`] snapshot and composes it
+//! with DB-derived counts + the session/browser flags.
 //!
 //! NOTE: this is per-process state. The deployment is a single server
 //! (see CLAUDE.md), so an in-memory handle is sufficient; durable signals
 //! (last-pass summary, runtime session) are persisted in `crawler_state`.
 
-use std::sync::Arc;
+use std::collections::HashMap;
+use std::sync::{Arc, Mutex};
 
 use chrono::{DateTime, Utc};
 use serde::Serialize;
@@ -21,8 +22,8 @@ use uuid::Uuid;
 
 use crate::crawler::pipeline::MetadataStats;
 
-/// What the daemon is doing right now. Serialised with an internal `state`
-/// tag so the frontend can switch on it.
+/// What the daemon's metadata pass is doing right now. Serialised with an
+/// internal `state` tag so the frontend can switch on it.
 #[derive(Clone, Debug, Serialize)]
 #[serde(tag = "state", rename_all = "snake_case")]
 pub enum Phase {
@@ -37,18 +38,30 @@ pub enum Phase {
         total: Option<usize>,
         title: String,
     },
-    /// Backfilling covers that failed on first attempt.
-    CoverBackfill,
+    /// Backfilling covers that failed on first attempt. `index`/`total`
+    /// track progress through this tick's batch.
+    CoverBackfill { index: usize, total: usize },
 }
 
-/// Per-worker activity. (Browser-restart and session-expired states are
-/// surfaced as separate top-level fields by the endpoint, sourced from the
-/// `BrowserManager` phase and the session flag respectively.)
+/// A chapter being downloaded right now, with a live page count. Keyed in
+/// the status by `chapter_id`; inserted by the dispatcher when a job starts
+/// and removed (via an RAII guard) when it finishes, panics, or times out.
 #[derive(Clone, Debug, Serialize)]
-#[serde(tag = "state", rename_all = "snake_case")]
-pub enum WorkerState {
-    Idle,
-    Working { chapter_id: Uuid },
+pub struct ActiveChapter {
+    pub manga_id: Uuid,
+    pub manga_title: String,
+    pub chapter_id: Uuid,
+    pub chapter_number: i32,
+    pub pages_done: usize,
+    /// `None` until the chapter page list has been parsed.
+    pub pages_total: Option<usize>,
+}
+
+/// The manga whose cover is being downloaded right now.
+#[derive(Clone, Debug, Serialize)]
+pub struct CoverTarget {
+    pub manga_id: Uuid,
+    pub manga_title: String,
 }
 
 /// Summary of the most recent metadata pass (persisted across restarts in
@@ -62,24 +75,30 @@ pub struct LastPass {
     pub mangas_failed: usize,
 }
 
-/// The mutable slice of status the daemon owns. Session/browser/queue are
-/// composed at read time by the endpoint (they live elsewhere), so they
-/// are not stored here.
+/// A point-in-time snapshot returned by [`StatusHandle::snapshot`]. The
+/// session/browser/queue fields are composed at read time by the endpoint
+/// (they live elsewhere), so they are not stored here.
 #[derive(Clone, Debug, Serialize)]
 pub struct CrawlerStatus {
     pub phase: Phase,
-    pub workers: Vec<WorkerState>,
+    /// Number of configured chapter workers (for "N busy / M workers").
+    pub worker_count: usize,
+    /// Chapters being downloaded right now, with live page counts.
+    pub active_chapters: Vec<ActiveChapter>,
     pub last_pass: LastPass,
+    /// The cover being downloaded right now, if any.
+    pub current_cover: Option<CoverTarget>,
 }
 
-impl CrawlerStatus {
-    fn new(num_workers: usize) -> Self {
-        Self {
-            phase: Phase::Idle { next_fire: None },
-            workers: (0..num_workers.max(1)).map(|_| WorkerState::Idle).collect(),
-            last_pass: LastPass::default(),
-        }
-    }
+/// Scalar status state held under the async `RwLock`. Active chapters live
+/// in a separate sync map so per-page updates and RAII removal don't need
+/// to `.await` (removal happens in `Drop`).
+#[derive(Clone, Debug)]
+struct Scalar {
+    phase: Phase,
+    worker_count: usize,
+    last_pass: LastPass,
+    current_cover: Option<CoverTarget>,
 }
 
 /// Cloneable handle the daemon tasks use to publish status. Cheap to clone
@@ -88,18 +107,35 @@ impl CrawlerStatus {
 /// get pushed an update instead of polling.
 #[derive(Clone)]
 pub struct StatusHandle {
-    inner: Arc<RwLock<CrawlerStatus>>,
-    /// Monotonic version bumped on every change. SSE handlers
-    /// `subscribe()` and `await .changed()` for instant pushes; `watch`
-    /// has no lost-wakeup so a change between snapshots is never missed.
+    scalar: Arc<RwLock<Scalar>>,
+    /// Currently-downloading chapters keyed by `chapter_id`. A sync mutex so
+    /// the RAII [`ChapterGuard`]'s `Drop` can remove without `.await`.
+    active: Arc<Mutex<HashMap<Uuid, ActiveChapter>>>,
+    /// Monotonic version bumped on every change. SSE handlers `subscribe()`
+    /// and `await .changed()` for instant pushes; `watch` has no
+    /// lost-wakeup so a change between snapshots is never missed.
     version: Arc<watch::Sender<u64>>,
 }
 
+/// Lock the active map, recovering from a poisoned mutex (we never hold the
+/// lock across a panic-prone section, so the data is still consistent).
+fn lock_active(
+    m: &Mutex<HashMap<Uuid, ActiveChapter>>,
+) -> std::sync::MutexGuard<'_, HashMap<Uuid, ActiveChapter>> {
+    m.lock().unwrap_or_else(|e| e.into_inner())
+}
+
 impl StatusHandle {
     pub fn new(num_workers: usize) -> Self {
         let (version, _rx) = watch::channel(0u64);
         Self {
-            inner: Arc::new(RwLock::new(CrawlerStatus::new(num_workers))),
+            scalar: Arc::new(RwLock::new(Scalar {
+                phase: Phase::Idle { next_fire: None },
+                worker_count: num_workers.max(1),
+                last_pass: LastPass::default(),
+                current_cover: None,
+            })),
+            active: Arc::new(Mutex::new(HashMap::new())),
             version: Arc::new(version),
         }
     }
@@ -122,15 +158,37 @@ impl StatusHandle {
     }
 
     pub async fn set_phase(&self, phase: Phase) {
-        self.inner.write().await.phase = phase;
+        self.scalar.write().await.phase = phase;
         self.bump();
     }
 
-    pub async fn set_worker(&self, id: usize, state: WorkerState) {
+    /// Set (or clear) the cover being downloaded right now.
+    pub async fn set_current_cover(&self, cover: Option<CoverTarget>) {
+        self.scalar.write().await.current_cover = cover;
+        self.bump();
+    }
+
+    /// Register a chapter as crawling now; returns a guard that removes it
+    /// when dropped (on completion, panic-unwind, or timeout-drop).
+    pub fn begin_chapter(&self, chapter: ActiveChapter) -> ChapterGuard {
+        let id = chapter.chapter_id;
+        lock_active(&self.active).insert(id, chapter);
+        self.bump();
+        ChapterGuard {
+            active: Arc::clone(&self.active),
+            version: Arc::clone(&self.version),
+            chapter_id: id,
+        }
+    }
+
+    /// Update the live page count of an in-flight chapter. Sync (no
+    /// `.await`) so it's cheap to call once per stored page.
+    pub fn set_chapter_pages(&self, chapter_id: Uuid, done: usize, total: Option<usize>) {
         {
-            let mut s = self.inner.write().await;
-            if let Some(slot) = s.workers.get_mut(id) {
-                *slot = state;
+            let mut map = lock_active(&self.active);
+            if let Some(c) = map.get_mut(&chapter_id) {
+                c.pages_done = done;
+                c.pages_total = total;
             }
         }
         self.bump();
@@ -138,28 +196,55 @@ impl StatusHandle {
 
     /// Record a finished metadata pass. Stamps `at` with `now`.
     pub async fn record_pass(&self, stats: &MetadataStats, at: DateTime<Utc>) {
-        {
-            let mut s = self.inner.write().await;
-            s.last_pass = LastPass {
-                at: Some(at),
-                discovered: stats.discovered,
-                upserted: stats.upserted,
-                covers_fetched: stats.covers_fetched,
-                mangas_failed: stats.mangas_failed,
-            };
-        }
+        self.scalar.write().await.last_pass = LastPass {
+            at: Some(at),
+            discovered: stats.discovered,
+            upserted: stats.upserted,
+            covers_fetched: stats.covers_fetched,
+            mangas_failed: stats.mangas_failed,
+        };
         self.bump();
     }
 
     /// Seed the last-pass summary from a persisted `crawler_state` value on
     /// startup so the dashboard isn't blank until the first tick.
     pub async fn set_last_pass(&self, last: LastPass) {
-        self.inner.write().await.last_pass = last;
+        self.scalar.write().await.last_pass = last;
         self.bump();
     }
 
     pub async fn snapshot(&self) -> CrawlerStatus {
-        self.inner.read().await.clone()
+        let scalar = self.scalar.read().await.clone();
+        let mut active_chapters: Vec<ActiveChapter> =
+            lock_active(&self.active).values().cloned().collect();
+        // Stable, readable order: by chapter number then id.
+        active_chapters.sort_by(|a, b| {
+            a.chapter_number
+                .cmp(&b.chapter_number)
+                .then(a.chapter_id.cmp(&b.chapter_id))
+        });
+        CrawlerStatus {
+            phase: scalar.phase,
+            worker_count: scalar.worker_count,
+            active_chapters,
+            last_pass: scalar.last_pass,
+            current_cover: scalar.current_cover,
+        }
+    }
+}
+
+/// RAII handle removing an [`ActiveChapter`] from the live status when the
+/// chapter dispatch finishes, panics, or is dropped on timeout.
+pub struct ChapterGuard {
+    active: Arc<Mutex<HashMap<Uuid, ActiveChapter>>>,
+    version: Arc<watch::Sender<u64>>,
+    chapter_id: Uuid,
+}
+
+impl Drop for ChapterGuard {
+    fn drop(&mut self) {
+        lock_active(&self.active).remove(&self.chapter_id);
+        self.version.send_modify(|v| *v = v.wrapping_add(1));
     }
 }
 
@@ -167,16 +252,73 @@ impl StatusHandle {
 mod tests {
     use super::*;
 
+    fn sample_chapter(n: i32) -> ActiveChapter {
+        ActiveChapter {
+            manga_id: Uuid::new_v4(),
+            manga_title: "M".into(),
+            chapter_id: Uuid::new_v4(),
+            chapter_number: n,
+            pages_done: 0,
+            pages_total: None,
+        }
+    }
+
     #[tokio::test]
-    async fn set_worker_updates_only_that_slot() {
+    async fn begin_chapter_shows_in_snapshot_and_guard_removes_on_drop() {
         let h = StatusHandle::new(2);
-        let cid = Uuid::new_v4();
-        h.set_worker(1, WorkerState::Working { chapter_id: cid }).await;
+        let chap = sample_chapter(7);
+        let cid = chap.chapter_id;
+        {
+            let _guard = h.begin_chapter(chap);
+            let snap = h.snapshot().await;
+            assert_eq!(snap.active_chapters.len(), 1);
+            assert_eq!(snap.active_chapters[0].chapter_id, cid);
+            assert_eq!(snap.worker_count, 2);
+        }
+        // Guard dropped → entry removed.
         let snap = h.snapshot().await;
-        assert!(matches!(snap.workers[0], WorkerState::Idle));
-        assert!(matches!(snap.workers[1], WorkerState::Working { .. }));
-        // Out-of-range id is a no-op, not a panic.
-        h.set_worker(99, WorkerState::Idle).await;
+        assert!(snap.active_chapters.is_empty());
+    }
+
+    #[tokio::test]
+    async fn set_chapter_pages_updates_live_count() {
+        let h = StatusHandle::new(1);
+        let chap = sample_chapter(1);
+        let cid = chap.chapter_id;
+        let _guard = h.begin_chapter(chap);
+        h.set_chapter_pages(cid, 3, Some(20));
+        let snap = h.snapshot().await;
+        assert_eq!(snap.active_chapters[0].pages_done, 3);
+        assert_eq!(snap.active_chapters[0].pages_total, Some(20));
+        // Updating an unknown chapter is a no-op, not a panic.
+        h.set_chapter_pages(Uuid::new_v4(), 9, Some(9));
+    }
+
+    #[tokio::test]
+    async fn snapshot_sorts_active_chapters_by_number() {
+        let h = StatusHandle::new(2);
+        let _g1 = h.begin_chapter(sample_chapter(5));
+        let _g2 = h.begin_chapter(sample_chapter(2));
+        let snap = h.snapshot().await;
+        assert_eq!(snap.active_chapters[0].chapter_number, 2);
+        assert_eq!(snap.active_chapters[1].chapter_number, 5);
+    }
+
+    #[tokio::test]
+    async fn set_current_cover_round_trips() {
+        let h = StatusHandle::new(1);
+        let mid = Uuid::new_v4();
+        h.set_current_cover(Some(CoverTarget {
+            manga_id: mid,
+            manga_title: "One Piece".into(),
+        }))
+        .await;
+        assert_eq!(
+            h.snapshot().await.current_cover.map(|c| c.manga_id),
+            Some(mid)
+        );
+        h.set_current_cover(None).await;
+        assert!(h.snapshot().await.current_cover.is_none());
     }
 
     #[tokio::test]
@@ -197,14 +339,17 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn subscribe_resolves_on_mutation_and_poke() {
+    async fn subscribe_resolves_on_mutation_poke_and_chapter_change() {
         let h = StatusHandle::new(1);
         let mut rx = h.subscribe();
-        // A mutation wakes the subscriber.
         h.set_phase(Phase::WalkingList).await;
         rx.changed().await.unwrap();
-        // A bare poke (external signal) also wakes it.
         h.poke();
         rx.changed().await.unwrap();
+        // begin_chapter + guard drop each bump the version.
+        let g = h.begin_chapter(sample_chapter(1));
+        rx.changed().await.unwrap();
+        drop(g);
+        rx.changed().await.unwrap();
     }
 }

backend/src/repo/chapter.rs

@@ -138,14 +138,18 @@ pub async fn page_count(pool: &PgPool, id: Uuid) -> sqlx::Result<Option<i32>> {
 /// filter — this resolver stays in lockstep so a chapter that was
 /// dropped between enqueue and lease isn't dispatched against a stale
 /// URL.
+/// Returns `(manga_id, source_url, manga_title, chapter_number)`. The
+/// title + number feed the live "currently crawling" status; the rest is
+/// what the dispatcher needs to do the work.
 pub async fn dispatch_target(
     pool: &PgPool,
     chapter_id: Uuid,
-) -> sqlx::Result<Option<(Uuid, String)>> {
+) -> sqlx::Result<Option<(Uuid, String, String, i32)>> {
     sqlx::query_as(
-        "SELECT c.manga_id, cs.source_url \
+        "SELECT c.manga_id, cs.source_url, m.title, c.number \
            FROM chapters c \
            JOIN chapter_sources cs ON cs.chapter_id = c.id \
+           JOIN mangas m ON m.id = c.manga_id \
           WHERE c.id = $1 \
             AND cs.dropped_at IS NULL \
           ORDER BY cs.last_seen_at DESC \

backend/src/repo/crawler.rs

@@ -699,6 +699,155 @@ pub async fn list_dead_jobs(
     Ok((items, total))
 }
 
+/// An in-flight chapter-content job (`pending` or `running`) joined to its
+/// chapter + manga, for the "queued chapters" admin view.
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct ActiveJob {
+    pub id: Uuid,
+    pub chapter_id: Option<Uuid>,
+    pub manga_id: Option<Uuid>,
+    pub manga_title: Option<String>,
+    pub chapter_number: Option<i32>,
+    /// `"pending"` or `"running"`.
+    pub state: String,
+    pub attempts: i32,
+    pub max_attempts: i32,
+    pub updated_at: DateTime<Utc>,
+}
+
+/// Paginated list of `pending`/`running` chapter-content jobs (which
+/// chapters of which mangas are queued or being crawled). Running first,
+/// then by scheduled order. `search` filters on manga title.
+pub async fn list_active_jobs(
+    pool: &PgPool,
+    search: Option<&str>,
+    limit: i64,
+    offset: i64,
+) -> sqlx::Result<(Vec<ActiveJob>, i64)> {
+    let search_pat = search
+        .map(|s| format!("%{}%", s.trim()))
+        .filter(|p| p.len() > 2);
+
+    let items: Vec<ActiveJob> = sqlx::query_as(
+        r#"
+        SELECT
+            cj.id,
+            (cj.payload->>'chapter_id')::uuid         AS chapter_id,
+            c.manga_id                                AS manga_id,
+            m.title                                   AS manga_title,
+            c.number                                  AS chapter_number,
+            cj.state,
+            cj.attempts,
+            cj.max_attempts,
+            cj.updated_at
+          FROM crawler_jobs cj
+          LEFT JOIN chapters c ON c.id = (cj.payload->>'chapter_id')::uuid
+          LEFT JOIN mangas m   ON m.id = c.manga_id
+         WHERE cj.state IN ('pending','running')
+           AND cj.payload->>'kind' = 'sync_chapter_content'
+           AND ($1::text IS NULL OR m.title ILIKE $1)
+         ORDER BY (cj.state = 'running') DESC, cj.scheduled_at, cj.created_at
+         LIMIT $2 OFFSET $3
+        "#,
+    )
+    .bind(&search_pat)
+    .bind(limit)
+    .bind(offset)
+    .fetch_all(pool)
+    .await?;
+
+    let total: i64 = sqlx::query_scalar(
+        r#"
+        SELECT COUNT(*)
+          FROM crawler_jobs cj
+          LEFT JOIN chapters c ON c.id = (cj.payload->>'chapter_id')::uuid
+          LEFT JOIN mangas m   ON m.id = c.manga_id
+         WHERE cj.state IN ('pending','running')
+           AND cj.payload->>'kind' = 'sync_chapter_content'
+           AND ($1::text IS NULL OR m.title ILIKE $1)
+        "#,
+    )
+    .bind(&search_pat)
+    .fetch_one(pool)
+    .await?;
+
+    Ok((items, total))
+}
+
+/// A manga whose cover is still missing (queued for cover fetch).
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct MissingCoverRow {
+    pub manga_id: Uuid,
+    pub manga_title: String,
+}
+
+/// Count mangas with no cover yet but a live source row — the cover
+/// backlog the metadata pass + backfill drain.
+pub async fn count_missing_covers(pool: &PgPool) -> sqlx::Result<i64> {
+    sqlx::query_scalar(
+        r#"
+        SELECT COUNT(*) FROM mangas m
+         WHERE m.cover_image_path IS NULL
+           AND EXISTS (
+               SELECT 1 FROM manga_sources ms
+                WHERE ms.manga_id = m.id AND ms.dropped_at IS NULL
+           )
+        "#,
+    )
+    .fetch_one(pool)
+    .await
+}
+
+/// Paginated list of mangas queued for a cover fetch (no cover yet + a live
+/// source), with titles. `search` filters on title. Freshest source first.
+pub async fn list_missing_cover_mangas(
+    pool: &PgPool,
+    search: Option<&str>,
+    limit: i64,
+    offset: i64,
+) -> sqlx::Result<(Vec<MissingCoverRow>, i64)> {
+    let search_pat = search
+        .map(|s| format!("%{}%", s.trim()))
+        .filter(|p| p.len() > 2);
+
+    let items: Vec<MissingCoverRow> = sqlx::query_as(
+        r#"
+        SELECT m.id AS manga_id, m.title AS manga_title
+          FROM mangas m
+         WHERE m.cover_image_path IS NULL
+           AND EXISTS (
+               SELECT 1 FROM manga_sources ms
+                WHERE ms.manga_id = m.id AND ms.dropped_at IS NULL
+           )
+           AND ($1::text IS NULL OR m.title ILIKE $1)
+         ORDER BY m.updated_at DESC
+         LIMIT $2 OFFSET $3
+        "#,
+    )
+    .bind(&search_pat)
+    .bind(limit)
+    .bind(offset)
+    .fetch_all(pool)
+    .await?;
+
+    let total: i64 = sqlx::query_scalar(
+        r#"
+        SELECT COUNT(*) FROM mangas m
+         WHERE m.cover_image_path IS NULL
+           AND EXISTS (
+               SELECT 1 FROM manga_sources ms
+                WHERE ms.manga_id = m.id AND ms.dropped_at IS NULL
+           )
+           AND ($1::text IS NULL OR m.title ILIKE $1)
+        "#,
+    )
+    .bind(&search_pat)
+    .fetch_one(pool)
+    .await?;
+
+    Ok((items, total))
+}
+
 /// Scope of a dead-job requeue.
 #[derive(Debug, Clone)]
 pub enum RequeueScope {

backend/tests/api_admin_crawler.rs

@@ -64,6 +64,102 @@ async fn seed_dead_job(pool: &PgPool, title: &str) -> Uuid {
     job_id
 }
 
+/// Seed a chapter-content job in a given state ('pending'/'running').
+async fn seed_job(pool: &PgPool, title: &str, state: &str) {
+    let manga_id = Uuid::new_v4();
+    let chapter_id = Uuid::new_v4();
+    sqlx::query("INSERT INTO mangas (id, title) VALUES ($1, $2)")
+        .bind(manga_id)
+        .bind(title)
+        .execute(pool)
+        .await
+        .unwrap();
+    sqlx::query("INSERT INTO chapters (id, manga_id, number) VALUES ($1, $2, 1)")
+        .bind(chapter_id)
+        .bind(manga_id)
+        .execute(pool)
+        .await
+        .unwrap();
+    sqlx::query("INSERT INTO crawler_jobs (id, payload, state) VALUES ($1, $2, $3)")
+        .bind(Uuid::new_v4())
+        .bind(json!({
+            "kind": "sync_chapter_content",
+            "source_id": "target",
+            "chapter_id": chapter_id,
+            "source_chapter_key": "k",
+        }))
+        .bind(state)
+        .execute(pool)
+        .await
+        .unwrap();
+}
+
+/// Seed a manga with no cover + a live source row (queued for cover fetch).
+async fn seed_missing_cover(pool: &PgPool, title: &str) {
+    let manga_id = Uuid::new_v4();
+    sqlx::query("INSERT INTO mangas (id, title, cover_image_path) VALUES ($1, $2, NULL)")
+        .bind(manga_id)
+        .bind(title)
+        .execute(pool)
+        .await
+        .unwrap();
+    sqlx::query("INSERT INTO sources (id, name, base_url) VALUES ('target','T','http://x') ON CONFLICT DO NOTHING")
+        .execute(pool)
+        .await
+        .unwrap();
+    sqlx::query(
+        "INSERT INTO manga_sources (source_id, source_manga_key, manga_id, source_url) \
+         VALUES ('target', $1, $2, 'http://x/m')",
+    )
+    .bind(format!("k-{manga_id}"))
+    .bind(manga_id)
+    .execute(pool)
+    .await
+    .unwrap();
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn active_jobs_and_covers_lists_over_http(pool: PgPool) {
+    seed_job(&pool, "Naruto", "pending").await;
+    seed_job(&pool, "Bleach", "running").await;
+    seed_missing_cover(&pool, "One Piece").await;
+    let h = harness(pool.clone());
+    let cookie = seed_admin(&pool, &h.app).await;
+
+    // Queued/active chapters.
+    let resp = h
+        .app
+        .clone()
+        .oneshot(get_with_cookie("/api/v1/admin/crawler/active-jobs", &cookie))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::OK);
+    let body = body_json(resp).await;
+    assert_eq!(body["page"]["total"], 2);
+
+    // Queued covers.
+    let resp = h
+        .app
+        .clone()
+        .oneshot(get_with_cookie("/api/v1/admin/crawler/covers", &cookie))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::OK);
+    let body = body_json(resp).await;
+    assert_eq!(body["page"]["total"], 1);
+    assert_eq!(body["items"][0]["manga_title"], "One Piece");
+
+    // Both are admin-gated.
+    let (_u, plain) = register_user(&h.app).await;
+    let resp = h
+        .app
+        .clone()
+        .oneshot(get_with_cookie("/api/v1/admin/crawler/active-jobs", &plain))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::FORBIDDEN);
+}
+
 #[sqlx::test(migrations = "./migrations")]
 async fn get_status_requires_admin(pool: PgPool) {
     let h = harness(pool);

backend/tests/crawler_dead_jobs.rs

@@ -7,6 +7,32 @@ use serde_json::json;
 use sqlx::PgPool;
 use uuid::Uuid;
 
+/// Seed a manga with no cover + a live source row (so it's "queued for a
+/// cover fetch"). Returns the manga id.
+async fn seed_missing_cover(pool: &PgPool, title: &str) -> Uuid {
+    let manga_id = Uuid::new_v4();
+    sqlx::query("INSERT INTO mangas (id, title, cover_image_path) VALUES ($1, $2, NULL)")
+        .bind(manga_id)
+        .bind(title)
+        .execute(pool)
+        .await
+        .unwrap();
+    sqlx::query("INSERT INTO sources (id, name, base_url) VALUES ('target', 'T', 'http://x') ON CONFLICT DO NOTHING")
+        .execute(pool)
+        .await
+        .unwrap();
+    sqlx::query(
+        "INSERT INTO manga_sources (source_id, source_manga_key, manga_id, source_url) \
+         VALUES ('target', $1, $2, 'http://x/m')",
+    )
+    .bind(format!("k-{manga_id}"))
+    .bind(manga_id)
+    .execute(pool)
+    .await
+    .unwrap();
+    manga_id
+}
+
 /// Seed a manga + chapter and return their ids.
 async fn seed_chapter(pool: &PgPool, title: &str, number: i32) -> (Uuid, Uuid) {
     let manga_id = Uuid::new_v4();
@@ -202,6 +228,66 @@ async fn requeue_with_two_dead_jobs_for_one_chapter_revives_one_not_500(pool: Pg
     }
 }
 
+#[sqlx::test(migrations = "./migrations")]
+async fn list_active_jobs_returns_pending_and_running_running_first(pool: PgPool) {
+    let (_m, c1) = seed_chapter(&pool, "Naruto", 700).await;
+    let (_m2, c2) = seed_chapter(&pool, "Bleach", 10).await;
+    insert_job(&pool, c1, "pending", 0).await;
+    insert_job(&pool, c2, "running", 1).await;
+    // A dead + a done job must NOT appear.
+    let (_m3, c3) = seed_chapter(&pool, "Gone", 1).await;
+    insert_job(&pool, c3, "dead", 5).await;
+
+    let (items, total) = crawler::list_active_jobs(&pool, None, 50, 0).await.unwrap();
+    assert_eq!(total, 2);
+    assert_eq!(items.len(), 2);
+    // Running first.
+    assert_eq!(items[0].state, "running");
+    assert_eq!(items[0].manga_title.as_deref(), Some("Bleach"));
+    assert_eq!(items[1].state, "pending");
+    assert_eq!(items[1].chapter_number, Some(700));
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn list_active_jobs_filters_by_title(pool: PgPool) {
+    let (_m, c1) = seed_chapter(&pool, "Naruto", 1).await;
+    let (_m2, c2) = seed_chapter(&pool, "One Piece", 1).await;
+    insert_job(&pool, c1, "pending", 0).await;
+    insert_job(&pool, c2, "pending", 0).await;
+    let (items, total) = crawler::list_active_jobs(&pool, Some("piece"), 50, 0)
+        .await
+        .unwrap();
+    assert_eq!(total, 1);
+    assert_eq!(items[0].manga_title.as_deref(), Some("One Piece"));
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn missing_covers_count_and_list(pool: PgPool) {
+    seed_missing_cover(&pool, "Naruto").await;
+    seed_missing_cover(&pool, "Bleach").await;
+    // A manga WITH a cover must not be counted.
+    let with_cover = Uuid::new_v4();
+    sqlx::query("INSERT INTO mangas (id, title, cover_image_path) VALUES ($1, 'Done', 'k.jpg')")
+        .bind(with_cover)
+        .execute(&pool)
+        .await
+        .unwrap();
+
+    assert_eq!(crawler::count_missing_covers(&pool).await.unwrap(), 2);
+
+    let (items, total) = crawler::list_missing_cover_mangas(&pool, None, 50, 0)
+        .await
+        .unwrap();
+    assert_eq!(total, 2);
+    assert_eq!(items.len(), 2);
+
+    let (items, total) = crawler::list_missing_cover_mangas(&pool, Some("naru"), 50, 0)
+        .await
+        .unwrap();
+    assert_eq!(total, 1);
+    assert_eq!(items[0].manga_title, "Naruto");
+}
+
 #[sqlx::test(migrations = "./migrations")]
 async fn job_state_counts_groups_by_state(pool: PgPool) {
     let (_m, c1) = seed_chapter(&pool, "A", 1).await;

backend/tests/repo_chapter.rs

@@ -109,7 +109,7 @@ async fn dispatch_target_prefers_most_recent_live_source(pool: PgPool) {
         seed_chapter_with_two_live_sources(&pool).await;
 
     let row = dispatch_target(&pool, chapter_id).await.unwrap();
-    let (_manga_id, source_url) =
+    let (_manga_id, source_url, _title, _number) =
         row.expect("two live sources should yield a dispatch target");
     assert_eq!(
         source_url, new_url,
@@ -133,7 +133,7 @@ async fn dispatch_target_skips_dropped_sources(pool: PgPool) {
     .unwrap();
 
     let row = dispatch_target(&pool, chapter_id).await.unwrap();
-    let (_manga_id, source_url) =
+    let (_manga_id, source_url, _title, _number) =
         row.expect("a single live source should still yield a dispatch target");
     assert!(
         source_url != new_url,