feat(chapter): preserve source-site order in chapter list (0.52.0)

The user-facing chapter list ordered by (number ASC, created_at ASC),
which broke the source site's order in two ways: non-numeric entries
("notice. : Officials") parsed to number=0 and clustered at the top,
even though the site placed them mid-list, and variants sharing a
number ("Ch.14 : PH" / "Ch.14 : Official") were torn apart by the
created_at tiebreak.

Capture each chapter's position in the source DOM as `source_index`
(0 = first = newest on this site) on every crawler sync, including the
UPDATE branch so a new chapter prepended on the source shifts every
existing row down by one on the next tick. The list query reverses
this with `ORDER BY source_index DESC NULLS LAST, number ASC,
created_at ASC` so the oldest chapter appears first, variants stay
adjacent in the order the site shows them, and non-numeric entries
land where the site placed them. User-uploaded chapters and pre-
migration rows keep their NULL source_index and fall through to the
prior number/created_at tiebreak via NULLS LAST.

The reader's client-side `[...chapters].sort((a,b) => a.number - b.number)`
is dropped; prev/next now walks the server-ordered array positionally
so it traverses variants and non-numeric entries in display order.

Existing data populates on the next cron tick or via admin force-resync.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/Cargo.lock

@@ -1470,7 +1470,7 @@ checksum = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"
 
 [[package]]
 name = "mangalord"
-version = "0.49.1"
+version = "0.52.0"
 dependencies = [
  "anyhow",
  "argon2",

backend/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mangalord"
-version = "0.49.1"
+version = "0.52.0"
 edition = "2021"
 default-run = "mangalord"
 

backend/migrations/0021_chapter_source_index.sql

@@ -0,0 +1,18 @@
+-- Capture each chapter's position in the source site's chapter list so
+-- the user-facing list can preserve site order: variants of the same
+-- chapter number (e.g. "Ch.14 : PH" next to "Ch.14 : Official") stay
+-- adjacent, and non-numeric entries like "notice. : Officials" land
+-- where the site placed them rather than clustering at the top under
+-- number = 0.
+--
+-- Lower source_index = closer to the top of the source DOM = newer
+-- chapter on this site (it renders newest-first). The list query
+-- reverses this with ORDER BY source_index DESC so the oldest chapter
+-- appears first in our UI.
+--
+-- NULL is the sentinel for user-uploaded chapters (no source row) and
+-- for crawled rows that pre-date this migration. The list query keeps
+-- the existing (number, created_at) tiebreak via NULLS LAST so those
+-- fall through to the prior behaviour until the next crawler tick
+-- populates the column.
+ALTER TABLE chapters ADD COLUMN source_index INTEGER;

backend/src/api/admin/mod.rs

@@ -5,6 +5,7 @@
 //! `crate::auth::extractor::RequireAdmin`).
 
 pub mod mangas;
+pub mod resync;
 pub mod system;
 pub mod users;
 
@@ -16,5 +17,6 @@ pub fn routes() -> Router<AppState> {
     Router::new()
         .merge(users::routes())
         .merge(mangas::routes())
+        .merge(resync::routes())
         .merge(system::routes())
 }

backend/src/api/admin/resync.rs

@@ -0,0 +1,176 @@
+//! Admin-triggered force resync of a single manga's metadata + cover,
+//! or a single chapter's content.
+//!
+//! Both endpoints are admin-only (`RequireAdmin`, cookie-only) and run
+//! synchronously with the request — the response carries the refreshed
+//! resource so the UI can swap it in without a follow-up GET. The work
+//! itself is delegated to [`ResyncService`] (set on AppState by
+//! `app::build` when the crawler daemon is enabled); when the daemon
+//! is disabled, both handlers return 503.
+
+use axum::extract::{Path, State};
+use axum::routing::post;
+use axum::{Json, Router};
+use serde::Serialize;
+use serde_json::json;
+use uuid::Uuid;
+
+use crate::app::AppState;
+use crate::auth::extractor::RequireAdmin;
+use crate::crawler::resync::{ChapterResyncOutcome, ResyncError};
+use crate::domain::manga::MangaDetail;
+use crate::domain::Chapter;
+use crate::error::{AppError, AppResult};
+use crate::repo;
+use crate::repo::crawler::UpsertStatus;
+
+pub fn routes() -> Router<AppState> {
+    Router::new()
+        .route("/admin/mangas/:id/resync", post(resync_manga))
+        .route("/admin/chapters/:id/resync", post(resync_chapter))
+}
+
+#[derive(Debug, Serialize)]
+pub struct MangaResyncResponse {
+    pub manga: MangaDetail,
+    /// `"new" | "updated" | "unchanged"` — mirrors [`UpsertStatus`].
+    pub metadata_status: &'static str,
+    pub cover_fetched: bool,
+}
+
+#[derive(Debug, Serialize)]
+pub struct ChapterResyncResponse {
+    pub chapter: Chapter,
+    /// `"fetched" | "skipped"` — whether new pages landed or the
+    /// service short-circuited (e.g. chapter already had pages and the
+    /// session was lost so force was downgraded).
+    pub outcome: &'static str,
+    /// Page count when `outcome == "fetched"`. `None` for `skipped`.
+    pub pages: Option<usize>,
+}
+
+async fn resync_manga(
+    State(state): State<AppState>,
+    admin: RequireAdmin,
+    Path(manga_id): Path<Uuid>,
+) -> AppResult<Json<MangaResyncResponse>> {
+    if !repo::manga::exists(&state.db, manga_id).await? {
+        return Err(AppError::NotFound);
+    }
+    let resync = state
+        .resync
+        .as_ref()
+        .ok_or_else(|| AppError::ServiceUnavailable(
+            "crawler daemon is disabled; force resync unavailable".into(),
+        ))?;
+
+    let outcome = resync.resync_manga(manga_id).await.map_err(map_resync_err)?;
+
+    // Audit the action with the actor + the resync outcome so an
+    // operator-of-operators can answer "who refetched this manga, and
+    // did the cover land?" from the log alone.
+    repo::admin_audit::insert(
+        &state.db,
+        admin.0.id,
+        "manga_resync",
+        "manga",
+        Some(manga_id),
+        json!({
+            "metadata_status": status_str(outcome.metadata_status),
+            "cover_fetched": outcome.cover_fetched,
+        }),
+    )
+    .await?;
+
+    let manga = repo::manga::get_detail(&state.db, manga_id).await?;
+    Ok(Json(MangaResyncResponse {
+        manga,
+        metadata_status: status_str(outcome.metadata_status),
+        cover_fetched: outcome.cover_fetched,
+    }))
+}
+
+async fn resync_chapter(
+    State(state): State<AppState>,
+    admin: RequireAdmin,
+    Path(chapter_id): Path<Uuid>,
+) -> AppResult<Json<ChapterResyncResponse>> {
+    let resync = state
+        .resync
+        .as_ref()
+        .ok_or_else(|| AppError::ServiceUnavailable(
+            "crawler daemon is disabled; force resync unavailable".into(),
+        ))?;
+
+    // Look up the manga the chapter belongs to so we can return the
+    // refreshed chapter row in the response and 404 for unknown ids.
+    let manga_id: Option<Uuid> =
+        sqlx::query_scalar("SELECT manga_id FROM chapters WHERE id = $1")
+            .bind(chapter_id)
+            .fetch_optional(&state.db)
+            .await?;
+    let Some(manga_id) = manga_id else {
+        return Err(AppError::NotFound);
+    };
+
+    let outcome = resync
+        .resync_chapter(chapter_id)
+        .await
+        .map_err(map_resync_err)?;
+
+    let (outcome_str, pages) = match &outcome {
+        ChapterResyncOutcome::Fetched { pages, .. } => ("fetched", Some(*pages)),
+        ChapterResyncOutcome::Skipped { .. } => ("skipped", None),
+    };
+
+    repo::admin_audit::insert(
+        &state.db,
+        admin.0.id,
+        "chapter_resync",
+        "chapter",
+        Some(chapter_id),
+        json!({
+            "outcome": outcome_str,
+            "pages": pages,
+        }),
+    )
+    .await?;
+
+    let chapter = repo::chapter::find_by_id_in_manga(&state.db, manga_id, chapter_id)
+        .await?
+        .ok_or(AppError::NotFound)?;
+    Ok(Json(ChapterResyncResponse {
+        chapter,
+        outcome: outcome_str,
+        pages,
+    }))
+}
+
+fn status_str(s: UpsertStatus) -> &'static str {
+    match s {
+        UpsertStatus::New => "new",
+        UpsertStatus::Updated => "updated",
+        UpsertStatus::Unchanged => "unchanged",
+    }
+}
+
+/// Map [`ResyncError`] (and the anyhow envelopes wrapping it) onto the
+/// right [`AppError`]. Anything else surfaces as a generic 500 via the
+/// `Other` arm — the operator sees the underlying anyhow chain in
+/// server logs, the client sees a clean envelope.
+fn map_resync_err(err: anyhow::Error) -> AppError {
+    if let Some(rerr) = err.downcast_ref::<ResyncError>() {
+        match rerr {
+            ResyncError::NoMangaSource => AppError::ValidationFailed {
+                message: "manga has no live crawler source — cannot resync".into(),
+                details: json!({ "manga": "no_source" }),
+            },
+            ResyncError::NoChapterSource => AppError::ValidationFailed {
+                message: "chapter has no live crawler source — cannot resync".into(),
+                details: json!({ "chapter": "no_source" }),
+            },
+        }
+    } else {
+        AppError::Other(err)
+    }
+}

backend/src/app.rs

@@ -24,6 +24,7 @@ use crate::crawler::daemon::{self, ChapterDispatcher, DaemonConfig, MetadataPass
 use crate::crawler::jobs::JobPayload;
 use crate::crawler::pipeline::{self, MetadataStats};
 use crate::crawler::rate_limit::HostRateLimiters;
+use crate::crawler::resync::{RealResyncService, ResyncService};
 use crate::crawler::safety::DownloadAllowlist;
 use crate::crawler::session;
 use crate::repo;
@@ -39,6 +40,12 @@ pub struct AppState {
     /// One instance per AppState so tests stay isolated across the
     /// same process.
     pub auth_limiter: Arc<AuthRateLimiter>,
+    /// Admin-triggered force resync. `None` when the crawler daemon
+    /// is disabled (`CRAWLER_DAEMON=false`); admin handlers gate on
+    /// `.is_some()` and return 503 otherwise. Set by [`build`] from the
+    /// same wiring that builds the daemon's chapter dispatcher, so a
+    /// force resync uses the daemon's BrowserManager + rate limiters.
+    pub resync: Option<Arc<dyn ResyncService>>,
 }
 
 /// Bundle returned by [`build`]. The router is what `axum::serve` consumes;
@@ -73,11 +80,12 @@ pub async fn build(config: Config) -> anyhow::Result<AppHandle> {
 
     let storage: Arc<dyn Storage> = Arc::new(LocalStorage::new(config.storage_dir.clone()));
 
-    let daemon = if config.crawler.daemon_enabled {
+    let (daemon, resync) = if config.crawler.daemon_enabled {
-        Some(spawn_crawler_daemon(db.clone(), Arc::clone(&storage), &config.crawler).await?)
+        let spawned = spawn_crawler_daemon(db.clone(), Arc::clone(&storage), &config.crawler).await?;
+        (Some(spawned.handle), Some(spawned.resync))
     } else {
         tracing::info!("crawler daemon disabled (CRAWLER_DAEMON=false)");
-        None
+        (None, None)
     };
 
     let auth_limiter = Arc::new(AuthRateLimiter::new(config.auth.rate_limit));
@@ -87,16 +95,26 @@ pub async fn build(config: Config) -> anyhow::Result<AppHandle> {
         auth: config.auth.clone(),
         upload: config.upload.clone(),
         auth_limiter,
+        resync,
     };
     let router = router(state).layer(cors_layer(&config.cors_allowed_origins));
     Ok(AppHandle { router, daemon })
 }
 
+/// Bundle returned by [`spawn_crawler_daemon`]. The handle owns the
+/// daemon's tasks; `resync` is the operator-trigger service shared with
+/// `AppState` so admin endpoints can call into the same browser /
+/// rate-limit machinery.
+struct SpawnedDaemon {
+    handle: daemon::DaemonHandle,
+    resync: Arc<dyn ResyncService>,
+}
+
 async fn spawn_crawler_daemon(
     db: PgPool,
     storage: Arc<dyn Storage>,
     cfg: &CrawlerConfig,
-) -> anyhow::Result<daemon::DaemonHandle> {
+) -> anyhow::Result<SpawnedDaemon> {
     // Reqwest client with cookie jar pre-seeded so CDN image fetches
     // include PHPSESSID. Same shape as bin/crawler.rs main().
     let cookie_jar = Arc::new(reqwest::cookie::Jar::default());
@@ -198,6 +216,17 @@ async fn spawn_crawler_daemon(
     });
 
     let dispatcher: Arc<dyn ChapterDispatcher> = Arc::new(RealChapterDispatcher {
+        browser_manager: Arc::clone(&browser_manager),
+        db: db.clone(),
+        storage: Arc::clone(&storage),
+        http: http.clone(),
+        rate: Arc::clone(&rate),
+        download_allowlist: cfg.download_allowlist.clone(),
+        max_image_bytes: cfg.max_image_bytes,
+        tor: tor.as_ref().map(Arc::clone),
+    });
+
+    let resync: Arc<dyn ResyncService> = Arc::new(RealResyncService {
         browser_manager: Arc::clone(&browser_manager),
         db: db.clone(),
         storage: Arc::clone(&storage),
@@ -242,7 +271,10 @@ async fn spawn_crawler_daemon(
         },
     );
 
-    Ok(daemon_handle)
+    Ok(SpawnedDaemon {
+        handle: daemon_handle,
+        resync,
+    })
 }
 
 // Real impls of the daemon traits, owning the browser manager + I/O. Kept
@@ -285,6 +317,36 @@ impl MetadataPass for RealMetadataPass {
                 self.browser_manager.invalidate().await;
             }
         }
+        // Cover backfill follows the metadata pass even when the pass
+        // 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.
+        match pipeline::backfill_missing_covers(
+            &self.browser_manager,
+            &self.db,
+            self.storage.as_ref(),
+            &self.http,
+            &self.rate,
+            pipeline::COVER_BACKFILL_DEFAULT_MAX,
+            &self.download_allowlist,
+            self.max_image_bytes,
+            self.tor.as_deref(),
+        )
+        .await
+        {
+            Ok(stats) => {
+                if stats.considered > 0 {
+                    tracing::info!(?stats, "cover backfill complete");
+                }
+            }
+            Err(e) => {
+                tracing::warn!(error = ?e, "cover backfill failed");
+                if crate::crawler::nav::anyhow_looks_browser_dead(&e) {
+                    self.browser_manager.invalidate().await;
+                }
+            }
+        }
         result
     }
 }

backend/src/crawler/jobs.rs

@@ -104,6 +104,12 @@ pub async fn enqueue(pool: &PgPool, payload: &JobPayload) -> sqlx::Result<Enqueu
 ///
 /// `kind_filter` matches against `payload->>'kind'`; `None` means
 /// any kind.
+///
+/// Ties on `scheduled_at` (the common case: a cron batch enqueues
+/// everything with the same default `now()`) break by `created_at`, so
+/// jobs come off the queue in insertion order. The enqueue paths insert
+/// chapter-content jobs in ascending `chapters.number` order, so this
+/// tiebreaker is what propagates that intent through to dequeue.
 pub async fn lease(
     pool: &PgPool,
     kind_filter: Option<&str>,
@@ -118,7 +124,7 @@ pub async fn lease(
              WHERE (state = 'pending' OR (state = 'running' AND leased_until < now()))
                AND scheduled_at <= now()
                AND ($1::text IS NULL OR payload->>'kind' = $1)
-             ORDER BY scheduled_at
+             ORDER BY scheduled_at, created_at
              LIMIT $2
              FOR UPDATE SKIP LOCKED
         )

backend/src/crawler/mod.rs

@@ -23,6 +23,7 @@ pub mod jobs;
 pub mod nav;
 pub mod pipeline;
 pub mod rate_limit;
+pub mod resync;
 pub mod safety;
 pub mod session;
 pub mod source;

backend/src/crawler/pipeline.rs

@@ -13,7 +13,7 @@ use crate::crawler::jobs::{self, EnqueueResult, JobPayload};
 use crate::crawler::rate_limit::HostRateLimiters;
 use crate::crawler::safety::{fetch_bytes_capped, looks_like_image, DownloadAllowlist};
 use crate::crawler::source::target::TargetSource;
-use crate::crawler::source::{FetchContext, Source};
+use crate::crawler::source::{FetchContext, Source, SourceMangaRef};
 use crate::repo;
 use crate::repo::crawler::UpsertStatus;
 use crate::storage::Storage;
@@ -429,8 +429,8 @@ pub async fn enqueue_bookmarked_pending(pool: &PgPool) -> anyhow::Result<Enqueue
                   AND cj.state = 'dead'
                   AND cj.updated_at > now() - ($1::bigint || ' days')::interval
            )
-         GROUP BY cs.source_id, c.id, cs.source_chapter_key, c.manga_id, c.created_at
+         GROUP BY cs.source_id, c.id, cs.source_chapter_key, c.manga_id, c.number, c.created_at
-         ORDER BY c.manga_id, c.created_at ASC
+         ORDER BY c.manga_id, c.number ASC, c.created_at ASC
         "#,
     )
     .bind(CHAPTER_DEAD_QUARANTINE_DAYS)
@@ -471,7 +471,7 @@ pub async fn enqueue_pending_for_manga(
 ) -> anyhow::Result<EnqueueSummary> {
     let rows: Vec<(String, Uuid, String)> = sqlx::query_as(
         r#"
-        SELECT DISTINCT cs.source_id, c.id AS chapter_id, cs.source_chapter_key
+        SELECT cs.source_id, c.id AS chapter_id, cs.source_chapter_key
           FROM chapters c
           JOIN chapter_sources cs ON cs.chapter_id = c.id
          WHERE c.manga_id = $1
@@ -484,7 +484,8 @@ pub async fn enqueue_pending_for_manga(
                   AND cj.state = 'dead'
                   AND cj.updated_at > now() - ($2::bigint || ' days')::interval
            )
-         ORDER BY cs.source_id, c.id
+         GROUP BY cs.source_id, c.id, cs.source_chapter_key, c.number, c.created_at
+         ORDER BY c.number ASC, c.created_at ASC, cs.source_id
         "#,
     )
     .bind(manga_id)
@@ -523,12 +524,133 @@ pub struct EnqueueSummary {
     pub failed: usize,
 }
 
+#[derive(Debug, Default, Clone, Copy)]
+pub struct CoverBackfillStats {
+    pub considered: usize,
+    pub fetched: usize,
+    pub failed: usize,
+}
+
+/// Default per-tick cap for [`backfill_missing_covers`]. The metadata pass
+/// already retries covers when its walk reaches the affected manga; this
+/// backfill exists to catch the residual case where the early-stop
+/// optimisation prevents the walk from reaching mangas whose cover failed
+/// on first attempt. A small cap is enough because the backlog only grows
+/// from sporadic download failures, not from systematic misses.
+pub const COVER_BACKFILL_DEFAULT_MAX: usize = 10;
+
+/// Re-attempt cover downloads for mangas where `cover_image_path IS NULL`
+/// but a live `manga_sources` row exists. Refetches the source detail
+/// page (which is where the cover URL lives) and downloads the cover.
+///
+/// Bounded by `max_mangas` per call so a steady stream of failing covers
+/// — e.g. a CDN host that's persistently 502 — can't monopolise a cron
+/// tick. Orders by `manga_sources.last_seen_at DESC` so the freshest
+/// missing-cover mangas are addressed first.
+///
+/// Failures are logged and counted, not raised: a single bad cover URL
+/// must not stall every other backfill behind it.
+#[allow(clippy::too_many_arguments)]
+pub async fn backfill_missing_covers(
+    browser_manager: &BrowserManager,
+    db: &PgPool,
+    storage: &dyn Storage,
+    http: &reqwest::Client,
+    rate: &HostRateLimiters,
+    max_mangas: usize,
+    allowlist: &DownloadAllowlist,
+    max_image_bytes: usize,
+    tor: Option<&crate::crawler::tor::TorController>,
+) -> anyhow::Result<CoverBackfillStats> {
+    let mut stats = CoverBackfillStats::default();
+    if max_mangas == 0 {
+        return Ok(stats);
+    }
+
+    let entries = repo::crawler::list_missing_covers(db, max_mangas as i64)
+        .await
+        .context("list_missing_covers")?;
+
+    if entries.is_empty() {
+        return Ok(stats);
+    }
+
+    let lease = browser_manager
+        .acquire()
+        .await
+        .context("acquire browser lease for cover backfill")?;
+    let browser_ref: &chromiumoxide::Browser = &lease;
+    let ctx = FetchContext { browser: browser_ref, rate, tor };
+
+    for entry in entries {
+        stats.considered += 1;
+        // 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.
+        let source = TargetSource::new(entry.source_url.clone()).without_chapter_parsing();
+        let r = SourceMangaRef {
+            source_manga_key: entry.source_manga_key.clone(),
+            title: String::new(),
+            url: entry.source_url.clone(),
+        };
+        let cover_url = match source.fetch_manga(&ctx, &r).await {
+            Ok(manga) => manga.cover_url,
+            Err(e) => {
+                tracing::warn!(
+                    manga_id = %entry.manga_id,
+                    url = %entry.source_url,
+                    error = ?e,
+                    "cover backfill: fetch_manga failed"
+                );
+                stats.failed += 1;
+                continue;
+            }
+        };
+        let Some(cover_url) = cover_url else {
+            tracing::warn!(
+                manga_id = %entry.manga_id,
+                url = %entry.source_url,
+                "cover backfill: source returned no cover_url"
+            );
+            stats.failed += 1;
+            continue;
+        };
+        match download_and_store_cover(
+            db,
+            storage,
+            http,
+            rate,
+            &entry.source_url,
+            entry.manga_id,
+            &cover_url,
+            allowlist,
+            max_image_bytes,
+        )
+        .await
+        {
+            Ok(()) => stats.fetched += 1,
+            Err(e) => {
+                tracing::warn!(
+                    manga_id = %entry.manga_id,
+                    url = %entry.source_url,
+                    error = ?e,
+                    "cover backfill: download failed"
+                );
+                stats.failed += 1;
+            }
+        }
+    }
+
+    drop(lease);
+    Ok(stats)
+}
+
 /// Download a cover image and persist its storage path. Local to the
 /// pipeline because the CLI still calls it from its inline chapter-content
 /// loop; once the worker pool fully replaces that path we can fold this
 /// into `pipeline` proper.
 #[allow(clippy::too_many_arguments)]
-async fn download_and_store_cover(
+pub(crate) async fn download_and_store_cover(
     db: &PgPool,
     storage: &dyn Storage,
     http: &reqwest::Client,

backend/src/crawler/resync.rs

@@ -0,0 +1,277 @@
+//! Admin-triggered resync of a single manga's metadata + cover, or a
+//! single chapter's content.
+//!
+//! The cron tick already retries covers and chapter content on its own
+//! schedule. This module exists for the operator-controlled path:
+//! "this manga's metadata is stale / its cover never landed / this
+//! chapter is broken — pull from source now, not at the next daily
+//! tick." Wired into the admin API, never into the queue, so the work
+//! happens synchronously with the HTTP request and the admin sees the
+//! refreshed row in the response.
+//!
+//! Shares the daemon's [`BrowserManager`], rate limiter, HTTP client,
+//! and TOR controller so a force resync respects the same per-host
+//! pacing and recircuit budget the daily crawl uses — admin actions
+//! must not let an operator accidentally hammer the source.
+
+use std::sync::Arc;
+
+use anyhow::Context;
+use async_trait::async_trait;
+use sqlx::PgPool;
+use uuid::Uuid;
+
+use crate::crawler::browser_manager::BrowserManager;
+use crate::crawler::content::{self, SyncOutcome};
+use crate::crawler::pipeline;
+use crate::crawler::rate_limit::HostRateLimiters;
+use crate::crawler::safety::DownloadAllowlist;
+use crate::crawler::source::target::TargetSource;
+use crate::crawler::source::{FetchContext, Source, SourceMangaRef};
+use crate::crawler::tor::TorController;
+use crate::repo;
+use crate::repo::crawler::UpsertStatus;
+use crate::storage::Storage;
+
+/// Outcome of [`ResyncService::resync_manga`]. Mirrors the bits the
+/// admin UI cares about — was the row actually re-upserted, did the
+/// cover land — so the response can show "metadata refreshed, cover
+/// re-downloaded" or "metadata unchanged" without a second round-trip.
+#[derive(Debug, Clone, Copy)]
+pub struct MangaResyncOutcome {
+    pub manga_id: Uuid,
+    pub metadata_status: UpsertStatus,
+    pub cover_fetched: bool,
+}
+
+/// Outcome of [`ResyncService::resync_chapter`]. `Fetched(pages)` is the
+/// success case; `Skipped` means the source row was already gone or the
+/// chapter had no live source.
+#[derive(Debug, Clone)]
+pub enum ChapterResyncOutcome {
+    Fetched { chapter_id: Uuid, pages: usize },
+    Skipped { chapter_id: Uuid, reason: String },
+}
+
+/// Service exposed by the daemon to the admin API. Optional on
+/// [`AppState`] — `None` when the crawler daemon is disabled
+/// (`CRAWLER_DAEMON=false`), in which case admin handlers return 503.
+#[async_trait]
+pub trait ResyncService: Send + Sync {
+    async fn resync_manga(&self, manga_id: Uuid) -> anyhow::Result<MangaResyncOutcome>;
+    async fn resync_chapter(&self, chapter_id: Uuid) -> anyhow::Result<ChapterResyncOutcome>;
+}
+
+/// Errors with a stable shape so the API layer can map them to the
+/// right HTTP status (404 vs 422 vs 5xx). Anything else surfaces as a
+/// generic 500.
+#[derive(Debug, thiserror::Error)]
+pub enum ResyncError {
+    #[error("manga has no source to resync from")]
+    NoMangaSource,
+    #[error("chapter has no source to resync from")]
+    NoChapterSource,
+}
+
+pub struct RealResyncService {
+    pub browser_manager: Arc<BrowserManager>,
+    pub db: PgPool,
+    pub storage: Arc<dyn Storage>,
+    pub http: reqwest::Client,
+    pub rate: Arc<HostRateLimiters>,
+    pub download_allowlist: DownloadAllowlist,
+    pub max_image_bytes: usize,
+    pub tor: Option<Arc<TorController>>,
+}
+
+#[async_trait]
+impl ResyncService for RealResyncService {
+    async fn resync_manga(&self, manga_id: Uuid) -> anyhow::Result<MangaResyncOutcome> {
+        // Pick the freshest live source row. Multi-source mangas
+        // (theoretical — only one Source impl today) get the row whose
+        // `last_seen_at` is newest; soft-dropped rows are skipped.
+        let row: Option<(String, String, String)> = sqlx::query_as(
+            "SELECT source_id, source_manga_key, source_url \
+               FROM manga_sources \
+              WHERE manga_id = $1 AND dropped_at IS NULL \
+              ORDER BY last_seen_at DESC \
+              LIMIT 1",
+        )
+        .bind(manga_id)
+        .fetch_optional(&self.db)
+        .await
+        .context("look up manga_sources for resync")?;
+        let Some((_source_id, source_manga_key, source_url)) = row else {
+            return Err(ResyncError::NoMangaSource.into());
+        };
+
+        let lease = self
+            .browser_manager
+            .acquire()
+            .await
+            .context("acquire browser lease for manga resync")?;
+        let browser_ref: &chromiumoxide::Browser = &lease;
+        let ctx = FetchContext {
+            browser: browser_ref,
+            rate: &self.rate,
+            tor: self.tor.as_deref(),
+        };
+
+        // Parse chapters too — a force resync is "make this manga fully
+        // current," not just metadata. The full pipeline handles the
+        // partial-render guard for us; we replicate the same caution
+        // here by skipping the chapter sync when the parser returned
+        // empty but the manga previously had chapters.
+        let source = TargetSource::new(source_url.clone());
+        let r = SourceMangaRef {
+            source_manga_key: source_manga_key.clone(),
+            title: String::new(),
+            url: source_url.clone(),
+        };
+        let manga = source
+            .fetch_manga(&ctx, &r)
+            .await
+            .with_context(|| format!("fetch_manga during resync of {manga_id}"))?;
+
+        // Partial-render guard: same logic as run_metadata_pass.
+        let source_id = source.id();
+        if !manga.chapters.is_empty() || {
+            let prior = repo::crawler::live_chapter_count_for_source_manga(
+                &self.db,
+                source_id,
+                &source_manga_key,
+            )
+            .await
+            .unwrap_or(0);
+            prior == 0
+        } {
+            // Either the new fetch surfaced chapters, or there were
+            // none before either — chapter sync is safe to run.
+        } else {
+            tracing::warn!(
+                %manga_id,
+                source_url = %source_url,
+                "resync_manga: fetch returned empty chapters but prior count > 0; skipping chapter sync to avoid soft-drop"
+            );
+        }
+
+        let upsert = repo::crawler::upsert_manga_from_source(
+            &self.db,
+            source_id,
+            &source_url,
+            &manga,
+        )
+        .await
+        .with_context(|| format!("upsert_manga_from_source during resync of {manga_id}"))?;
+
+        // Cover refetch: force-download regardless of UpsertStatus.
+        // Admin clicked "resync" because they want the cover too.
+        let mut cover_fetched = false;
+        if let Some(cover_url) = manga.cover_url.as_deref() {
+            match pipeline::download_and_store_cover(
+                &self.db,
+                self.storage.as_ref(),
+                &self.http,
+                &self.rate,
+                &source_url,
+                upsert.manga_id,
+                cover_url,
+                &self.download_allowlist,
+                self.max_image_bytes,
+            )
+            .await
+            {
+                Ok(()) => cover_fetched = true,
+                Err(e) => tracing::warn!(
+                    %manga_id,
+                    error = ?e,
+                    "resync_manga: cover download failed"
+                ),
+            }
+        }
+
+        // Chapter sync — only when the partial-render guard above
+        // didn't bail.
+        let prior_chapter_count = repo::crawler::live_chapter_count_for_source_manga(
+            &self.db,
+            source_id,
+            &source_manga_key,
+        )
+        .await
+        .unwrap_or(0);
+        if !manga.chapters.is_empty() || prior_chapter_count == 0 {
+            match repo::crawler::sync_manga_chapters(
+                &self.db,
+                source_id,
+                upsert.manga_id,
+                &manga.chapters,
+            )
+            .await
+            {
+                Ok(diff) => tracing::info!(
+                    %manga_id,
+                    new = diff.new,
+                    refreshed = diff.refreshed,
+                    dropped = diff.dropped,
+                    "resync_manga: chapters synced"
+                ),
+                Err(e) => tracing::warn!(
+                    %manga_id,
+                    error = ?e,
+                    "resync_manga: chapter sync failed"
+                ),
+            }
+        }
+
+        drop(lease);
+        Ok(MangaResyncOutcome {
+            manga_id: upsert.manga_id,
+            metadata_status: upsert.status,
+            cover_fetched,
+        })
+    }
+
+    async fn resync_chapter(&self, chapter_id: Uuid) -> anyhow::Result<ChapterResyncOutcome> {
+        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 {
+            return Err(ResyncError::NoChapterSource.into());
+        };
+
+        let lease = self
+            .browser_manager
+            .acquire()
+            .await
+            .context("acquire browser lease for chapter resync")?;
+        let result = content::sync_chapter_content(
+            &lease,
+            &self.db,
+            self.storage.as_ref(),
+            &self.http,
+            &self.rate,
+            chapter_id,
+            manga_id,
+            &source_url,
+            true,
+            &self.download_allowlist,
+            self.max_image_bytes,
+            self.tor.as_deref(),
+        )
+        .await;
+        drop(lease);
+
+        match result? {
+            SyncOutcome::Fetched { pages } => {
+                Ok(ChapterResyncOutcome::Fetched { chapter_id, pages })
+            }
+            SyncOutcome::Skipped => Ok(ChapterResyncOutcome::Skipped {
+                chapter_id,
+                reason: "chapter already had pages on disk".to_string(),
+            }),
+            SyncOutcome::SessionExpired => {
+                anyhow::bail!("source session expired — operator must refresh PHPSESSID")
+            }
+        }
+    }
+}

backend/src/error.rs

@@ -21,6 +21,11 @@ pub enum AppError {
     PayloadTooLarge(String),
     #[error("unsupported media type: {0}")]
     UnsupportedMediaType(String),
+    /// 503 — a feature is currently unavailable, distinct from a 5xx
+    /// internal error. Used when admin actions require the crawler
+    /// daemon but it's been disabled (`CRAWLER_DAEMON=false`).
+    #[error("service unavailable: {0}")]
+    ServiceUnavailable(String),
     /// 429 with an optional `Retry-After` header value (in seconds).
     #[error("too many requests")]
     TooManyRequests {
@@ -56,6 +61,7 @@ impl AppError {
             AppError::Conflict(_) => "conflict",
             AppError::PayloadTooLarge(_) => "payload_too_large",
             AppError::UnsupportedMediaType(_) => "unsupported_media_type",
+            AppError::ServiceUnavailable(_) => "service_unavailable",
             AppError::TooManyRequests { .. } => "too_many_requests",
             AppError::ValidationFailed { .. } => "validation_failed",
             AppError::Database(sqlx::Error::RowNotFound) => "not_found",
@@ -85,6 +91,9 @@ impl IntoResponse for AppError {
             AppError::UnsupportedMediaType(msg) => {
                 (StatusCode::UNSUPPORTED_MEDIA_TYPE, msg.clone(), None)
             }
+            AppError::ServiceUnavailable(msg) => {
+                (StatusCode::SERVICE_UNAVAILABLE, msg.clone(), None)
+            }
             AppError::TooManyRequests { retry_after_secs } => {
                 // Emit `Retry-After: N` (RFC 6585 §4) so a well-behaved
                 // client can back off correctly. Done by building the

backend/src/repo/chapter.rs

@@ -12,15 +12,20 @@ pub async fn list_for_manga(
     limit: i64,
     offset: i64,
 ) -> AppResult<Vec<Chapter>> {
-    // Secondary sort by created_at gives duplicate-numbered chapters
+    // Display order = source-site order reversed. The crawler stamps
-    // (multiple uploaders/translations of the same number) a stable
+    // `source_index` = position in the source DOM (0 = first = newest
-    // order in lists and prev/next reader navigation.
+    // on this site, see migration 0021), so DESC puts the oldest
+    // chapter first and keeps the site's variant grouping and the
+    // placement of non-numeric entries (e.g. "notice. : Officials")
+    // intact. NULLS LAST keeps user-uploaded chapters (no source row)
+    // and rows that pre-date the migration below crawled rows; the
+    // (number, created_at) tail then orders them deterministically.
     let rows = sqlx::query_as::<_, Chapter>(
         r#"
         SELECT id, manga_id, number, title, page_count, created_at
         FROM chapters
         WHERE manga_id = $1
-        ORDER BY number ASC, created_at ASC
+        ORDER BY source_index DESC NULLS LAST, number ASC, created_at ASC
         LIMIT $2 OFFSET $3
         "#,
     )

backend/src/repo/crawler.rs

@@ -352,7 +352,14 @@ pub async fn sync_manga_chapters(
         .map(|c| c.source_chapter_key.clone())
         .collect();
 
-    for c in chapters {
+    for (idx, c) in chapters.iter().enumerate() {
+        // `source_index` captures the chapter's position in the source
+        // DOM (0 = first = newest on this site) so the list query can
+        // reverse it for the user-facing list — see migration 0021.
+        // Every sync overwrites the value on both branches, so a new
+        // chapter inserted at the top of the source shifts every other
+        // row down by one on the next tick.
+        let source_index = idx as i32;
         // Lookup is constrained by manga_id (via the chapters join) so a
         // source whose chapter slugs collide across mangas (e.g.
         // "chapter-1" appearing under two different mangas) attributes
@@ -382,14 +389,15 @@ pub async fn sync_manga_chapters(
                 // identity is the UUID, not the number.
                 let (chapter_id,): (Uuid,) = sqlx::query_as(
                     r#"
-                    INSERT INTO chapters (manga_id, number, title, page_count)
+                    INSERT INTO chapters (manga_id, number, title, page_count, source_index)
-                    VALUES ($1, $2, $3, 0)
+                    VALUES ($1, $2, $3, 0, $4)
                     RETURNING id
                     "#,
                 )
                 .bind(manga_id)
                 .bind(c.number)
                 .bind(c.title.as_deref())
+                .bind(source_index)
                 .fetch_one(&mut *tx)
                 .await?;
                 sqlx::query(
@@ -408,8 +416,11 @@ pub async fn sync_manga_chapters(
                 diff.new += 1;
             }
             Some((chapter_id,)) => {
-                sqlx::query("UPDATE chapters SET title = $1 WHERE id = $2")
+                sqlx::query(
+                    "UPDATE chapters SET title = $1, source_index = $2 WHERE id = $3",
+                )
                     .bind(c.title.as_deref())
+                    .bind(source_index)
                     .bind(chapter_id)
                     .execute(&mut *tx)
                     .await?;
@@ -542,6 +553,51 @@ pub async fn mark_run_completed(pool: &PgPool, source_id: &str) -> sqlx::Result<
     Ok(())
 }
 
+/// List mangas whose `cover_image_path IS NULL` but a live
+/// `manga_sources` row still attaches them to a source. The bounded
+/// result feeds the cover-backfill pass in [`crate::crawler::pipeline`]:
+/// each entry is one (manga, freshest source row) pair where a cover
+/// re-download is in order.
+///
+/// Per-manga deduplication uses `DISTINCT ON (m.id)` keyed on the row
+/// with the newest `last_seen_at`, so a manga that's surfaced by
+/// multiple sources only produces one row (the freshest). Sort is
+/// stable for tests.
+pub async fn list_missing_covers(
+    pool: &PgPool,
+    max: i64,
+) -> sqlx::Result<Vec<MissingCoverEntry>> {
+    let rows: Vec<(Uuid, String, String)> = sqlx::query_as(
+        r#"
+        SELECT DISTINCT ON (m.id) m.id, ms.source_manga_key, ms.source_url
+          FROM mangas m
+          JOIN manga_sources ms ON ms.manga_id = m.id
+         WHERE m.cover_image_path IS NULL
+           AND ms.dropped_at IS NULL
+         ORDER BY m.id, ms.last_seen_at DESC
+         LIMIT $1
+        "#,
+    )
+    .bind(max)
+    .fetch_all(pool)
+    .await?;
+    Ok(rows
+        .into_iter()
+        .map(|(manga_id, source_manga_key, source_url)| MissingCoverEntry {
+            manga_id,
+            source_manga_key,
+            source_url,
+        })
+        .collect())
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct MissingCoverEntry {
+    pub manga_id: Uuid,
+    pub source_manga_key: String,
+    pub source_url: String,
+}
+
 /// Read the recovery flag for `source_id`. A missing row OR an
 /// unparseable value reads as `true` ("clean") — the former covers the
 /// first-ever run on a virgin DB (no recovery needed), the latter

backend/tests/api_admin_resync.rs

@@ -0,0 +1,350 @@
+//! Integration tests for the admin force-resync endpoints.
+//!
+//! Real resync work requires Chromium, so these tests swap in a stub
+//! [`ResyncService`] to assert the handler-level contract: routing,
+//! admin gate, 503 when the daemon is disabled, 404 / 422 mapping for
+//! missing-resource / no-source cases, and the audit-log side effect.
+
+mod common;
+
+use std::sync::Arc;
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use async_trait::async_trait;
+use axum::http::StatusCode;
+use serde_json::json;
+use sqlx::PgPool;
+use tower::ServiceExt;
+use uuid::Uuid;
+
+use mangalord::crawler::resync::{
+    ChapterResyncOutcome, MangaResyncOutcome, ResyncError, ResyncService,
+};
+use mangalord::repo;
+use mangalord::repo::crawler::UpsertStatus;
+
+/// Stub that records call counts and returns a canned outcome.
+struct StubResync {
+    manga_calls: AtomicUsize,
+    chapter_calls: AtomicUsize,
+    /// When true, returns NoMangaSource / NoChapterSource.
+    no_source: bool,
+}
+
+impl StubResync {
+    fn new() -> Arc<Self> {
+        Arc::new(Self {
+            manga_calls: AtomicUsize::new(0),
+            chapter_calls: AtomicUsize::new(0),
+            no_source: false,
+        })
+    }
+    fn no_source() -> Arc<Self> {
+        Arc::new(Self {
+            manga_calls: AtomicUsize::new(0),
+            chapter_calls: AtomicUsize::new(0),
+            no_source: true,
+        })
+    }
+}
+
+#[async_trait]
+impl ResyncService for StubResync {
+    async fn resync_manga(&self, manga_id: Uuid) -> anyhow::Result<MangaResyncOutcome> {
+        self.manga_calls.fetch_add(1, Ordering::SeqCst);
+        if self.no_source {
+            return Err(ResyncError::NoMangaSource.into());
+        }
+        Ok(MangaResyncOutcome {
+            manga_id,
+            metadata_status: UpsertStatus::Updated,
+            cover_fetched: true,
+        })
+    }
+    async fn resync_chapter(&self, chapter_id: Uuid) -> anyhow::Result<ChapterResyncOutcome> {
+        self.chapter_calls.fetch_add(1, Ordering::SeqCst);
+        if self.no_source {
+            return Err(ResyncError::NoChapterSource.into());
+        }
+        Ok(ChapterResyncOutcome::Fetched {
+            chapter_id,
+            pages: 7,
+        })
+    }
+}
+
+async fn promote_admin(pool: &PgPool, username: &str) {
+    let u = repo::user::find_by_username(pool, username)
+        .await
+        .unwrap()
+        .unwrap();
+    repo::user::set_is_admin_unchecked(pool, u.id, true)
+        .await
+        .unwrap();
+}
+
+async fn insert_manga(pool: &PgPool, title: &str) -> Uuid {
+    let (id,): (Uuid,) = sqlx::query_as(
+        "INSERT INTO mangas (title, status, alt_titles) VALUES ($1, 'ongoing', ARRAY[]::text[]) RETURNING id",
+    )
+    .bind(title)
+    .fetch_one(pool)
+    .await
+    .unwrap();
+    id
+}
+
+async fn insert_chapter(pool: &PgPool, manga_id: Uuid, number: i32, pages: i32) -> Uuid {
+    let (id,): (Uuid,) = sqlx::query_as(
+        "INSERT INTO chapters (manga_id, number, title, page_count) VALUES ($1, $2, NULL, $3) RETURNING id",
+    )
+    .bind(manga_id)
+    .bind(number)
+    .bind(pages)
+    .fetch_one(pool)
+    .await
+    .unwrap();
+    id
+}
+
+// ----- manga resync ---------------------------------------------------------
+
+#[sqlx::test(migrations = "./migrations")]
+async fn manga_resync_calls_service_and_returns_refreshed_detail(pool: PgPool) {
+    let stub = StubResync::new();
+    let h = common::harness_with_resync(pool.clone(), stub.clone());
+    let (username, cookie) = common::register_user(&h.app).await;
+    promote_admin(&pool, &username).await;
+    let manga_id = insert_manga(&pool, "Hello").await;
+
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/mangas/{manga_id}/resync"),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::OK);
+    let body = common::body_json(resp).await;
+    // Stub returned Updated + cover_fetched=true.
+    assert_eq!(body["metadata_status"], "updated");
+    assert_eq!(body["cover_fetched"], true);
+    // Response includes the refreshed manga detail.
+    assert_eq!(body["manga"]["id"], manga_id.to_string());
+    assert_eq!(body["manga"]["title"], "Hello");
+
+    assert_eq!(stub.manga_calls.load(Ordering::SeqCst), 1);
+
+    // Audit row written.
+    let (audit_count,): (i64,) =
+        sqlx::query_as("SELECT count(*) FROM admin_audit WHERE action = 'manga_resync' AND target_id = $1")
+            .bind(manga_id)
+            .fetch_one(&pool)
+            .await
+            .unwrap();
+    assert_eq!(audit_count, 1);
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn manga_resync_returns_404_for_unknown_id(pool: PgPool) {
+    let stub = StubResync::new();
+    let h = common::harness_with_resync(pool.clone(), stub.clone());
+    let (username, cookie) = common::register_user(&h.app).await;
+    promote_admin(&pool, &username).await;
+
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/mangas/{}/resync", Uuid::new_v4()),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::NOT_FOUND);
+    // Service must not have been called when the manga doesn't exist.
+    assert_eq!(stub.manga_calls.load(Ordering::SeqCst), 0);
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn manga_resync_maps_no_source_to_422(pool: PgPool) {
+    let stub = StubResync::no_source();
+    let h = common::harness_with_resync(pool.clone(), stub);
+    let (username, cookie) = common::register_user(&h.app).await;
+    promote_admin(&pool, &username).await;
+    let manga_id = insert_manga(&pool, "Manual upload, no crawler source").await;
+
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/mangas/{manga_id}/resync"),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::UNPROCESSABLE_ENTITY);
+    let body = common::body_json(resp).await;
+    assert_eq!(body["error"]["details"]["manga"], "no_source");
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn manga_resync_returns_503_when_daemon_disabled(pool: PgPool) {
+    let h = common::harness(pool.clone());
+    let (username, cookie) = common::register_user(&h.app).await;
+    promote_admin(&pool, &username).await;
+    let manga_id = insert_manga(&pool, "Z").await;
+
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/mangas/{manga_id}/resync"),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::SERVICE_UNAVAILABLE);
+    let body = common::body_json(resp).await;
+    assert_eq!(body["error"]["code"], "service_unavailable");
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn manga_resync_requires_admin(pool: PgPool) {
+    let stub = StubResync::new();
+    let h = common::harness_with_resync(pool.clone(), stub);
+    // Non-admin user.
+    let (_u, cookie) = common::register_user(&h.app).await;
+    let manga_id = insert_manga(&pool, "M").await;
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/mangas/{manga_id}/resync"),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::FORBIDDEN);
+}
+
+// ----- chapter resync -------------------------------------------------------
+
+#[sqlx::test(migrations = "./migrations")]
+async fn chapter_resync_calls_service_and_returns_refreshed_chapter(pool: PgPool) {
+    let stub = StubResync::new();
+    let h = common::harness_with_resync(pool.clone(), stub.clone());
+    let (username, cookie) = common::register_user(&h.app).await;
+    promote_admin(&pool, &username).await;
+    let manga_id = insert_manga(&pool, "M").await;
+    let chapter_id = insert_chapter(&pool, manga_id, 1, 0).await;
+
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/chapters/{chapter_id}/resync"),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::OK);
+    let body = common::body_json(resp).await;
+    assert_eq!(body["outcome"], "fetched");
+    assert_eq!(body["pages"], 7);
+    assert_eq!(body["chapter"]["id"], chapter_id.to_string());
+    assert_eq!(stub.chapter_calls.load(Ordering::SeqCst), 1);
+
+    let (audit_count,): (i64,) = sqlx::query_as(
+        "SELECT count(*) FROM admin_audit WHERE action = 'chapter_resync' AND target_id = $1",
+    )
+    .bind(chapter_id)
+    .fetch_one(&pool)
+    .await
+    .unwrap();
+    assert_eq!(audit_count, 1);
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn chapter_resync_returns_404_for_unknown_id(pool: PgPool) {
+    let stub = StubResync::new();
+    let h = common::harness_with_resync(pool.clone(), stub.clone());
+    let (username, cookie) = common::register_user(&h.app).await;
+    promote_admin(&pool, &username).await;
+
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/chapters/{}/resync", Uuid::new_v4()),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::NOT_FOUND);
+    assert_eq!(stub.chapter_calls.load(Ordering::SeqCst), 0);
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn chapter_resync_maps_no_source_to_422(pool: PgPool) {
+    let stub = StubResync::no_source();
+    let h = common::harness_with_resync(pool.clone(), stub);
+    let (username, cookie) = common::register_user(&h.app).await;
+    promote_admin(&pool, &username).await;
+    let manga_id = insert_manga(&pool, "M").await;
+    let chapter_id = insert_chapter(&pool, manga_id, 1, 0).await;
+
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/chapters/{chapter_id}/resync"),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::UNPROCESSABLE_ENTITY);
+    let body = common::body_json(resp).await;
+    assert_eq!(body["error"]["details"]["chapter"], "no_source");
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn chapter_resync_returns_503_when_daemon_disabled(pool: PgPool) {
+    let h = common::harness(pool.clone());
+    let (username, cookie) = common::register_user(&h.app).await;
+    promote_admin(&pool, &username).await;
+    let manga_id = insert_manga(&pool, "M").await;
+    let chapter_id = insert_chapter(&pool, manga_id, 1, 0).await;
+
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/chapters/{chapter_id}/resync"),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::SERVICE_UNAVAILABLE);
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn chapter_resync_requires_admin(pool: PgPool) {
+    let stub = StubResync::new();
+    let h = common::harness_with_resync(pool.clone(), stub);
+    let (_u, cookie) = common::register_user(&h.app).await;
+    let manga_id = insert_manga(&pool, "M").await;
+    let chapter_id = insert_chapter(&pool, manga_id, 1, 0).await;
+    let resp = h
+        .app
+        .oneshot(common::post_json_with_cookie(
+            &format!("/api/v1/admin/chapters/{chapter_id}/resync"),
+            json!({}),
+            &cookie,
+        ))
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::FORBIDDEN);
+}

backend/tests/api_admin_role.rs

@@ -49,6 +49,7 @@ fn admin_test_router(pool: PgPool) -> (Router, TempDir) {
         auth,
         upload: UploadConfig::default(),
         auth_limiter,
+        resync: None,
     };
     let app = Router::new()
         .nest("/api/v1", api::routes())

backend/tests/common/mod.rs

@@ -74,6 +74,10 @@ fn harness_with_auth_config(
             max_file_bytes: 256 * 1024,
         },
         auth_limiter,
+        // Default harness has no crawler daemon wired up; admin resync
+        // handlers return 503 in this config. Tests that need a stub
+        // resync service swap it in via `harness_with_resync`.
+        resync: None,
     };
     Harness { app: router(state), _storage_dir: storage_dir }
 }
@@ -124,6 +128,37 @@ pub fn harness_with_auth_rate_limit(
     harness_with_auth_config(pool, storage, storage_dir, auth)
 }
 
+/// Like [`harness`] but slots a caller-supplied [`ResyncService`] stub
+/// into `AppState.resync`. Used by the admin resync tests so the
+/// endpoint path is exercised without standing up a real Chromium.
+pub fn harness_with_resync(
+    pool: PgPool,
+    resync: Arc<dyn mangalord::crawler::resync::ResyncService>,
+) -> Harness {
+    let storage_dir = tempfile::tempdir().expect("tempdir");
+    let storage = Arc::new(LocalStorage::new(storage_dir.path()));
+    let auth = AuthConfig {
+        cookie_secure: false,
+        ..AuthConfig::default()
+    };
+    let auth_limiter = Arc::new(AuthRateLimiter::new(auth.rate_limit));
+    let state = AppState {
+        db: pool,
+        storage,
+        auth,
+        upload: UploadConfig {
+            max_request_bytes: 4 * 1024 * 1024,
+            max_file_bytes: 256 * 1024,
+        },
+        auth_limiter,
+        resync: Some(resync),
+    };
+    Harness {
+        app: router(state),
+        _storage_dir: storage_dir,
+    }
+}
+
 /// Wraps a real `Storage` and fails on the N-th `put` call so tests can
 /// assert that handlers roll their DB writes back when storage errors
 /// mid-upload. Reads and other operations delegate to `inner`.

backend/tests/crawler_daemon.rs

@@ -517,3 +517,132 @@ async fn enqueue_bookmarked_pending_resumes_after_quarantine_expires(pool: PgPoo
     );
 }
 
+/// Helper: insert a chapter with the given `number` and a non-dropped
+/// source row, returning the chapter id. Used by the ordering tests so
+/// the setup boilerplate doesn't drown the assertion.
+async fn insert_pending_chapter(
+    pool: &PgPool,
+    manga_id: Uuid,
+    number: i32,
+    source_chapter_key: &str,
+) -> Uuid {
+    let chapter_id: Uuid = sqlx::query_scalar(
+        "INSERT INTO chapters (manga_id, number, page_count) VALUES ($1, $2, 0) RETURNING id",
+    )
+    .bind(manga_id)
+    .bind(number)
+    .fetch_one(pool)
+    .await
+    .unwrap();
+    sqlx::query(
+        "INSERT INTO chapter_sources (source_id, source_chapter_key, chapter_id, source_url) \
+         VALUES ($1, $2, $3, $4)",
+    )
+    .bind("target")
+    .bind(source_chapter_key)
+    .bind(chapter_id)
+    .bind(format!("https://example.com/{source_chapter_key}"))
+    .execute(pool)
+    .await
+    .unwrap();
+    chapter_id
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn enqueue_bookmarked_pending_queues_chapters_in_ascending_number_order(pool: PgPool) {
+    // Insert chapters with `number` values 3, 1, 2 in that insertion
+    // order — so `created_at` order (the previous tiebreaker) does NOT
+    // match number order. After enqueue + lease, the worker should see
+    // chapters 1, 2, 3 in that sequence.
+    let user_id: Uuid = sqlx::query_scalar(
+        "INSERT INTO users (username, password_hash) VALUES ($1, $2) RETURNING id",
+    )
+    .bind("alice")
+    .bind("not-a-real-hash")
+    .fetch_one(&pool)
+    .await
+    .unwrap();
+    let manga_id: Uuid = sqlx::query_scalar("INSERT INTO mangas (title) VALUES ($1) RETURNING id")
+        .bind("Test")
+        .fetch_one(&pool)
+        .await
+        .unwrap();
+    sqlx::query(
+        "INSERT INTO sources (id, name, base_url) VALUES ($1, $2, $3) ON CONFLICT DO NOTHING",
+    )
+    .bind("target")
+    .bind("Target")
+    .bind("https://example.com")
+    .execute(&pool)
+    .await
+    .unwrap();
+    let c3 = insert_pending_chapter(&pool, manga_id, 3, "ch3").await;
+    let c1 = insert_pending_chapter(&pool, manga_id, 1, "ch1").await;
+    let c2 = insert_pending_chapter(&pool, manga_id, 2, "ch2").await;
+    sqlx::query("INSERT INTO bookmarks (user_id, manga_id) VALUES ($1, $2)")
+        .bind(user_id)
+        .bind(manga_id)
+        .execute(&pool)
+        .await
+        .unwrap();
+
+    let summary = pipeline::enqueue_bookmarked_pending(&pool).await.unwrap();
+    assert_eq!(summary.inserted, 3);
+
+    let leases = jobs::lease(&pool, None, 10, std::time::Duration::from_secs(60))
+        .await
+        .unwrap();
+    let leased_chapter_ids: Vec<Uuid> = leases
+        .iter()
+        .map(|l| match &l.payload {
+            JobPayload::SyncChapterContent { chapter_id, .. } => *chapter_id,
+            other => panic!("unexpected payload kind: {other:?}"),
+        })
+        .collect();
+    assert_eq!(
+        leased_chapter_ids,
+        vec![c1, c2, c3],
+        "chapters must be leased in ascending chapter-number order, not insertion order"
+    );
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn enqueue_pending_for_manga_queues_chapters_in_ascending_number_order(pool: PgPool) {
+    // Same scenario as above but exercising the bookmark-create hook path
+    // (`enqueue_pending_for_manga`) which has its own ORDER BY.
+    let manga_id: Uuid = sqlx::query_scalar("INSERT INTO mangas (title) VALUES ($1) RETURNING id")
+        .bind("Test")
+        .fetch_one(&pool)
+        .await
+        .unwrap();
+    sqlx::query(
+        "INSERT INTO sources (id, name, base_url) VALUES ($1, $2, $3) ON CONFLICT DO NOTHING",
+    )
+    .bind("target")
+    .bind("Target")
+    .bind("https://example.com")
+    .execute(&pool)
+    .await
+    .unwrap();
+    let c3 = insert_pending_chapter(&pool, manga_id, 3, "ch3").await;
+    let c1 = insert_pending_chapter(&pool, manga_id, 1, "ch1").await;
+    let c2 = insert_pending_chapter(&pool, manga_id, 2, "ch2").await;
+
+    let summary = pipeline::enqueue_pending_for_manga(&pool, manga_id)
+        .await
+        .unwrap();
+    assert_eq!(summary.inserted, 3);
+
+    let leases = jobs::lease(&pool, None, 10, std::time::Duration::from_secs(60))
+        .await
+        .unwrap();
+    let leased_chapter_ids: Vec<Uuid> = leases
+        .iter()
+        .map(|l| match &l.payload {
+            JobPayload::SyncChapterContent { chapter_id, .. } => *chapter_id,
+            other => panic!("unexpected payload kind: {other:?}"),
+        })
+        .collect();
+    assert_eq!(leased_chapter_ids, vec![c1, c2, c3]);
+}
+

backend/tests/crawler_jobs.rs

@@ -531,6 +531,89 @@ async fn reap_done_deletes_old_rows_keeps_fresh(pool: PgPool) {
     assert_eq!(remaining, vec![fresh_id], "only fresh row remains");
 }
 
+#[sqlx::test(migrations = "./migrations")]
+async fn lease_ties_on_scheduled_at_break_by_created_at(pool: PgPool) {
+    // Locks in the tiebreaker that lets enqueue order survive the lease
+    // step: when many jobs share `scheduled_at` (the common cron-batch
+    // case), the worker must pick the earliest-inserted row, not whatever
+    // Postgres returns in heap order. The enqueue path inserts chapters
+    // in chapter-number order, so this tiebreaker is what makes "queue
+    // in rising order" observable at the dequeue side too.
+    let a = match jobs::enqueue(&pool, &chapter_content_payload(Uuid::new_v4()))
+        .await
+        .unwrap()
+    {
+        EnqueueResult::Inserted(id) => id,
+        _ => unreachable!(),
+    };
+    let b = match jobs::enqueue(&pool, &chapter_content_payload(Uuid::new_v4()))
+        .await
+        .unwrap()
+    {
+        EnqueueResult::Inserted(id) => id,
+        _ => unreachable!(),
+    };
+    let c = match jobs::enqueue(&pool, &chapter_content_payload(Uuid::new_v4()))
+        .await
+        .unwrap()
+    {
+        EnqueueResult::Inserted(id) => id,
+        _ => unreachable!(),
+    };
+
+    // Pin `scheduled_at` to a single literal instant (shared across all
+    // three rows — `now()` would yield a different microsecond per UPDATE
+    // and make scheduled_at the actual sort key). Reverse `created_at`
+    // against insertion order so heap order would give the wrong answer.
+    let shared_scheduled = chrono::Utc::now() - chrono::Duration::hours(1);
+    sqlx::query(
+        "UPDATE crawler_jobs \
+            SET scheduled_at = $2, \
+                created_at   = $3 \
+          WHERE id = $1",
+    )
+    .bind(a)
+    .bind(shared_scheduled)
+    .bind(chrono::Utc::now() - chrono::Duration::seconds(10))
+    .execute(&pool)
+    .await
+    .unwrap();
+    sqlx::query(
+        "UPDATE crawler_jobs \
+            SET scheduled_at = $2, \
+                created_at   = $3 \
+          WHERE id = $1",
+    )
+    .bind(b)
+    .bind(shared_scheduled)
+    .bind(chrono::Utc::now() - chrono::Duration::seconds(20))
+    .execute(&pool)
+    .await
+    .unwrap();
+    sqlx::query(
+        "UPDATE crawler_jobs \
+            SET scheduled_at = $2, \
+                created_at   = $3 \
+          WHERE id = $1",
+    )
+    .bind(c)
+    .bind(shared_scheduled)
+    .bind(chrono::Utc::now() - chrono::Duration::seconds(30))
+    .execute(&pool)
+    .await
+    .unwrap();
+
+    let leases = jobs::lease(&pool, None, 10, Duration::from_secs(60))
+        .await
+        .unwrap();
+    let order: Vec<Uuid> = leases.iter().map(|l| l.id).collect();
+    assert_eq!(
+        order,
+        vec![c, b, a],
+        "lease must return jobs in created_at order when scheduled_at ties"
+    );
+}
+
 #[sqlx::test(migrations = "./migrations")]
 async fn reap_done_zero_is_a_no_op(pool: PgPool) {
     let id = match jobs::enqueue(&pool, &chapter_content_payload(Uuid::new_v4()))

backend/tests/crawler_sync.rs

@@ -6,6 +6,7 @@
 
 use mangalord::crawler::source::{SourceChapterRef, SourceManga};
 use mangalord::repo::crawler::{self, ChapterDiff, UpsertStatus};
+use mangalord::repo::chapter as chapter_repo;
 use sqlx::PgPool;
 use uuid::Uuid;
 
@@ -829,6 +830,107 @@ async fn sync_tags_garbage_collects_orphan_user_attachments(pool: PgPool) {
     assert_eq!(orphan_rows, 0, "orphan user-attached tag should be reaped");
 }
 
+// ---- list_missing_covers ---------------------------------------------------
+
+#[sqlx::test(migrations = "./migrations")]
+async fn list_missing_covers_only_returns_rows_without_cover(pool: PgPool) {
+    crawler::ensure_source(&pool, "target", "T", "https://x.example")
+        .await
+        .unwrap();
+    let with_cover = sample_manga("with", "With Cover", "h1");
+    let without_cover = sample_manga("without", "No Cover", "h2");
+    let _w = crawler::upsert_manga_from_source(&pool, "target", "https://x.example/with", &with_cover)
+        .await
+        .unwrap();
+    let nc = crawler::upsert_manga_from_source(&pool, "target", "https://x.example/without", &without_cover)
+        .await
+        .unwrap();
+
+    // Manually set a cover for `with` only.
+    sqlx::query("UPDATE mangas SET cover_image_path = 'mangas/x/cover.jpg' WHERE id = $1")
+        .bind(_w.manga_id)
+        .execute(&pool)
+        .await
+        .unwrap();
+
+    let entries = crawler::list_missing_covers(&pool, 50).await.unwrap();
+    assert_eq!(entries.len(), 1, "exactly the manga without a cover");
+    assert_eq!(entries[0].manga_id, nc.manga_id);
+    assert_eq!(entries[0].source_manga_key, "without");
+    assert_eq!(entries[0].source_url, "https://x.example/without");
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn list_missing_covers_skips_dropped_source_rows(pool: PgPool) {
+    crawler::ensure_source(&pool, "target", "T", "https://x.example")
+        .await
+        .unwrap();
+    let m = sample_manga("foo", "Foo", "h1");
+    let up = crawler::upsert_manga_from_source(&pool, "target", "https://x.example/foo", &m)
+        .await
+        .unwrap();
+    sqlx::query("UPDATE manga_sources SET dropped_at = NOW() WHERE manga_id = $1")
+        .bind(up.manga_id)
+        .execute(&pool)
+        .await
+        .unwrap();
+
+    let entries = crawler::list_missing_covers(&pool, 50).await.unwrap();
+    assert!(
+        entries.is_empty(),
+        "dropped-source mangas must not be backfilled — no live source to fetch from"
+    );
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn list_missing_covers_respects_limit(pool: PgPool) {
+    crawler::ensure_source(&pool, "target", "T", "https://x.example")
+        .await
+        .unwrap();
+    for i in 0..5 {
+        let key = format!("m{i}");
+        let url = format!("https://x.example/{key}");
+        let m = sample_manga(&key, &format!("M{i}"), &format!("h{i}"));
+        let _ = crawler::upsert_manga_from_source(&pool, "target", &url, &m)
+            .await
+            .unwrap();
+    }
+    let entries = crawler::list_missing_covers(&pool, 3).await.unwrap();
+    assert_eq!(entries.len(), 3, "limit caps the result set");
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn list_missing_covers_deduplicates_per_manga(pool: PgPool) {
+    // A manga surfaced by two sources should produce ONE backfill
+    // entry, not two — otherwise the per-tick cap could be eaten by
+    // duplicates and starve other mangas.
+    crawler::ensure_source(&pool, "src-a", "A", "https://a.example")
+        .await
+        .unwrap();
+    crawler::ensure_source(&pool, "src-b", "B", "https://b.example")
+        .await
+        .unwrap();
+    let m = sample_manga("foo", "Foo", "h1");
+    let up = crawler::upsert_manga_from_source(&pool, "src-a", "https://a.example/foo", &m)
+        .await
+        .unwrap();
+    // Second source attaches to the SAME manga row.
+    sqlx::query(
+        "INSERT INTO manga_sources (source_id, source_manga_key, manga_id, source_url) \
+         VALUES ($1, $2, $3, $4)",
+    )
+    .bind("src-b")
+    .bind("foo-on-b")
+    .bind(up.manga_id)
+    .bind("https://b.example/foo")
+    .execute(&pool)
+    .await
+    .unwrap();
+
+    let entries = crawler::list_missing_covers(&pool, 50).await.unwrap();
+    assert_eq!(entries.len(), 1, "DISTINCT ON (m.id) collapses duplicate source rows");
+}
+
 #[sqlx::test(migrations = "./migrations")]
 async fn re_appearing_manga_clears_dropped_at(pool: PgPool) {
     crawler::ensure_source(&pool, "target", "T", "https://x.example")
@@ -860,3 +962,261 @@ async fn re_appearing_manga_clears_dropped_at(pool: PgPool) {
     assert!(dropped.0.is_none());
     assert_eq!(dropped.1, up.manga_id);
 }
+
+// ---- source_index: site-order preservation ----
+//
+// The user-facing chapter list reverses the source-site order so that
+// the oldest chapter appears first. The crawler records each row's DOM
+// position in `chapters.source_index` (0 = first in source DOM = newest
+// on this site) on every sync; the list query orders by source_index
+// DESC NULLS LAST, falling through to number/created_at for rows with
+// no source row (e.g. user uploads).
+
+#[sqlx::test(migrations = "./migrations")]
+async fn source_index_set_on_insert_matches_dom_order(pool: PgPool) {
+    crawler::ensure_source(&pool, "target", "T", "https://x.example")
+        .await
+        .unwrap();
+    let m = sample_manga("foo", "Foo Manga", "hash-1");
+    let up = crawler::upsert_manga_from_source(&pool, "target", "https://x.example/foo", &m)
+        .await
+        .unwrap();
+
+    let chapters = vec![
+        SourceChapterRef {
+            source_chapter_key: "a".into(),
+            number: 30,
+            title: Some("Ch.30".into()),
+            url: "https://x.example/foo/a".into(),
+        },
+        SourceChapterRef {
+            source_chapter_key: "b".into(),
+            number: 29,
+            title: Some("Ch.29".into()),
+            url: "https://x.example/foo/b".into(),
+        },
+        SourceChapterRef {
+            source_chapter_key: "c".into(),
+            number: 28,
+            title: Some("Ch.28".into()),
+            url: "https://x.example/foo/c".into(),
+        },
+    ];
+    crawler::sync_manga_chapters(&pool, "target", up.manga_id, &chapters)
+        .await
+        .unwrap();
+
+    let rows: Vec<(String, Option<i32>)> = sqlx::query_as(
+        "SELECT cs.source_chapter_key, c.source_index \
+           FROM chapters c \
+           JOIN chapter_sources cs ON cs.chapter_id = c.id \
+          WHERE c.manga_id = $1 \
+          ORDER BY cs.source_chapter_key",
+    )
+    .bind(up.manga_id)
+    .fetch_all(&pool)
+    .await
+    .unwrap();
+    assert_eq!(
+        rows,
+        vec![
+            ("a".to_string(), Some(0)),
+            ("b".to_string(), Some(1)),
+            ("c".to_string(), Some(2)),
+        ],
+        "source_index reflects enumerate() position in the input slice",
+    );
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn source_index_rewritten_on_resync_when_new_chapter_prepended(pool: PgPool) {
+    crawler::ensure_source(&pool, "target", "T", "https://x.example")
+        .await
+        .unwrap();
+    let m = sample_manga("foo", "Foo Manga", "hash-1");
+    let up = crawler::upsert_manga_from_source(&pool, "target", "https://x.example/foo", &m)
+        .await
+        .unwrap();
+
+    let first = vec![
+        SourceChapterRef {
+            source_chapter_key: "a".into(),
+            number: 1,
+            title: Some("Ch.1".into()),
+            url: "https://x.example/foo/a".into(),
+        },
+        SourceChapterRef {
+            source_chapter_key: "b".into(),
+            number: 2,
+            title: Some("Ch.2".into()),
+            url: "https://x.example/foo/b".into(),
+        },
+    ];
+    crawler::sync_manga_chapters(&pool, "target", up.manga_id, &first)
+        .await
+        .unwrap();
+
+    // Second sync: a brand-new chapter appears at the top of the source
+    // (newest first on the site). All existing rows must shift their
+    // source_index down by one so the display order stays correct.
+    let second = vec![
+        SourceChapterRef {
+            source_chapter_key: "new".into(),
+            number: 3,
+            title: Some("Ch.3".into()),
+            url: "https://x.example/foo/new".into(),
+        },
+        SourceChapterRef {
+            source_chapter_key: "a".into(),
+            number: 1,
+            title: Some("Ch.1".into()),
+            url: "https://x.example/foo/a".into(),
+        },
+        SourceChapterRef {
+            source_chapter_key: "b".into(),
+            number: 2,
+            title: Some("Ch.2".into()),
+            url: "https://x.example/foo/b".into(),
+        },
+    ];
+    crawler::sync_manga_chapters(&pool, "target", up.manga_id, &second)
+        .await
+        .unwrap();
+
+    let rows: Vec<(String, Option<i32>)> = sqlx::query_as(
+        "SELECT cs.source_chapter_key, c.source_index \
+           FROM chapters c \
+           JOIN chapter_sources cs ON cs.chapter_id = c.id \
+          WHERE c.manga_id = $1 \
+          ORDER BY cs.source_chapter_key",
+    )
+    .bind(up.manga_id)
+    .fetch_all(&pool)
+    .await
+    .unwrap();
+    assert_eq!(
+        rows,
+        vec![
+            ("a".to_string(), Some(1)),
+            ("b".to_string(), Some(2)),
+            ("new".to_string(), Some(0)),
+        ],
+        "new chapter takes index 0, existing rows shift down on UPDATE",
+    );
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn list_for_manga_returns_source_order_reversed(pool: PgPool) {
+    crawler::ensure_source(&pool, "target", "T", "https://x.example")
+        .await
+        .unwrap();
+    let m = sample_manga("foo", "Foo Manga", "hash-1");
+    let up = crawler::upsert_manga_from_source(&pool, "target", "https://x.example/foo", &m)
+        .await
+        .unwrap();
+
+    // Site DOM order (top-down = newest-first):
+    //   ch11  (number = 11)
+    //   notice (number = 0, non-numeric label on the site)
+    //   ch10  (number = 10)
+    // Numbers deliberately disagree with DOM order: a number-based sort
+    // would put notice first, but the site places it between ch10 and
+    // ch11. Reversed-DOM display should yield [ch10, notice, ch11].
+    let chapters = vec![
+        SourceChapterRef {
+            source_chapter_key: "ch11".into(),
+            number: 11,
+            title: Some("Ch.11 : Official".into()),
+            url: "https://x.example/foo/11".into(),
+        },
+        SourceChapterRef {
+            source_chapter_key: "notice".into(),
+            number: 0,
+            title: Some("notice. : Officials".into()),
+            url: "https://x.example/foo/notice".into(),
+        },
+        SourceChapterRef {
+            source_chapter_key: "ch10".into(),
+            number: 10,
+            title: Some("Ch.10 : Official".into()),
+            url: "https://x.example/foo/10".into(),
+        },
+    ];
+    crawler::sync_manga_chapters(&pool, "target", up.manga_id, &chapters)
+        .await
+        .unwrap();
+
+    let listed = chapter_repo::list_for_manga(&pool, up.manga_id, 50, 0)
+        .await
+        .unwrap();
+    let keys: Vec<String> = listed
+        .iter()
+        .map(|c| c.title.clone().unwrap_or_default())
+        .collect();
+    assert_eq!(
+        keys,
+        vec![
+            "Ch.10 : Official".to_string(),
+            "notice. : Officials".to_string(),
+            "Ch.11 : Official".to_string(),
+        ],
+        "list returns chapters in reversed source-DOM order, so the \
+         oldest appears first and non-numeric entries land where the \
+         site placed them",
+    );
+}
+
+#[sqlx::test(migrations = "./migrations")]
+async fn list_for_manga_places_null_source_index_last(pool: PgPool) {
+    crawler::ensure_source(&pool, "target", "T", "https://x.example")
+        .await
+        .unwrap();
+    let m = sample_manga("foo", "Foo Manga", "hash-1");
+    let up = crawler::upsert_manga_from_source(&pool, "target", "https://x.example/foo", &m)
+        .await
+        .unwrap();
+
+    // Crawled chapters get source_index 0 and 1; the upload path leaves
+    // it NULL. NULLS LAST plus the (number, created_at) tail means the
+    // upload sits after both crawled rows even though its number is in
+    // the middle.
+    let crawled = vec![
+        SourceChapterRef {
+            source_chapter_key: "a".into(),
+            number: 1,
+            title: Some("Ch.1".into()),
+            url: "https://x.example/foo/a".into(),
+        },
+        SourceChapterRef {
+            source_chapter_key: "b".into(),
+            number: 3,
+            title: Some("Ch.3".into()),
+            url: "https://x.example/foo/b".into(),
+        },
+    ];
+    crawler::sync_manga_chapters(&pool, "target", up.manga_id, &crawled)
+        .await
+        .unwrap();
+
+    chapter_repo::create(&pool, up.manga_id, 2, Some("User upload Ch.2"), None)
+        .await
+        .unwrap();
+
+    let listed = chapter_repo::list_for_manga(&pool, up.manga_id, 50, 0)
+        .await
+        .unwrap();
+    let titles: Vec<String> = listed
+        .iter()
+        .map(|c| c.title.clone().unwrap_or_default())
+        .collect();
+    assert_eq!(
+        titles,
+        vec![
+            "Ch.3".to_string(),
+            "Ch.1".to_string(),
+            "User upload Ch.2".to_string(),
+        ],
+        "crawled rows ordered by reversed source_index; user upload \
+         (NULL source_index) falls through to the end",
+    );
+}

frontend/e2e/reader-chapter-select.spec.ts

@@ -0,0 +1,167 @@
+import { test, expect, type Page } from '@playwright/test';
+
+const mangaId = '33333333-3333-3333-3333-333333333333';
+const chapter1Id = 'c1111111-3333-3333-3333-333333333333';
+const chapter2Id = 'c2222222-3333-3333-3333-333333333333';
+const chapter3Id = 'c3333333-3333-3333-3333-333333333333';
+
+const mangaFixture = {
+    id: mangaId,
+    title: 'Vinland Saga',
+    author: 'Makoto Yukimura',
+    description: null,
+    cover_image_path: null,
+    created_at: '2026-01-01T00:00:00Z',
+    updated_at: '2026-01-01T00:00:00Z'
+};
+
+const chaptersFixture = [
+    {
+        id: chapter1Id,
+        manga_id: mangaId,
+        number: 1,
+        title: 'Somewhere, Not Here',
+        page_count: 1,
+        created_at: '2026-01-01T00:00:00Z'
+    },
+    {
+        id: chapter2Id,
+        manga_id: mangaId,
+        number: 2,
+        title: null,
+        page_count: 1,
+        created_at: '2026-01-02T00:00:00Z'
+    },
+    {
+        id: chapter3Id,
+        manga_id: mangaId,
+        number: 3,
+        title: 'Sword Dance',
+        page_count: 1,
+        created_at: '2026-01-03T00:00:00Z'
+    }
+];
+
+function pageFixture(chapterId: string) {
+    return [
+        {
+            id: `p1111111-${chapterId.slice(1, 8)}-3333-3333-333333333333`,
+            chapter_id: chapterId,
+            page_number: 1,
+            storage_key: `mangas/${mangaId}/chapters/${chapterId}/pages/0001.png`,
+            content_type: 'image/png'
+        }
+    ];
+}
+
+async function mockReaderApis(page: Page) {
+    // Force public mode so the layout doesn't bounce anonymous visitors
+    // to /login (the dev backend on this machine runs with
+    // PRIVATE_MODE=true, which the layout's universal load respects).
+    await page.route('**/api/v1/auth/config', (route) =>
+        route.fulfill({
+            status: 200,
+            contentType: 'application/json',
+            body: JSON.stringify({ self_register_enabled: true, private_mode: false })
+        })
+    );
+    await page.route('**/api/v1/auth/me', (route) =>
+        route.fulfill({
+            status: 401,
+            contentType: 'application/json',
+            body: JSON.stringify({ error: { code: 'unauthenticated', message: '' } })
+        })
+    );
+    await page.route('**/api/v1/auth/me/preferences', (route) =>
+        route.fulfill({
+            status: 401,
+            contentType: 'application/json',
+            body: JSON.stringify({ error: { code: 'unauthenticated', message: '' } })
+        })
+    );
+    await page.route('**/api/v1/me/bookmarks*', (route) =>
+        route.fulfill({
+            status: 401,
+            contentType: 'application/json',
+            body: JSON.stringify({ error: { code: 'unauthenticated', message: '' } })
+        })
+    );
+    await page.route(`**/api/v1/mangas/${mangaId}`, (route) =>
+        route.fulfill({
+            status: 200,
+            contentType: 'application/json',
+            body: JSON.stringify(mangaFixture)
+        })
+    );
+    await page.route(new RegExp(`/api/v1/mangas/${mangaId}/chapters(\\?.*)?$`), (route) =>
+        route.fulfill({
+            status: 200,
+            contentType: 'application/json',
+            body: JSON.stringify({
+                items: chaptersFixture,
+                page: { limit: 200, offset: 0, total: chaptersFixture.length }
+            })
+        })
+    );
+    for (const c of chaptersFixture) {
+        await page.route(`**/api/v1/mangas/${mangaId}/chapters/${c.id}`, (route) =>
+            route.fulfill({
+                status: 200,
+                contentType: 'application/json',
+                body: JSON.stringify(c)
+            })
+        );
+        await page.route(
+            `**/api/v1/mangas/${mangaId}/chapters/${c.id}/pages`,
+            (route) =>
+                route.fulfill({
+                    status: 200,
+                    contentType: 'application/json',
+                    body: JSON.stringify({ pages: pageFixture(c.id) })
+                })
+        );
+    }
+    const png = Buffer.from(
+        '89504e470d0a1a0a0000000d49484452000000010000000108060000001f15c4890000000d49444154789c63000100000005000158a3b62a0000000049454e44ae426082',
+        'hex'
+    );
+    await page.route('**/api/v1/files/**', (route) =>
+        route.fulfill({ status: 200, contentType: 'image/png', body: png })
+    );
+}
+
+test('reader chapter select lists every chapter with the manga-detail-style label', async ({
+    page
+}) => {
+    await mockReaderApis(page);
+    await page.goto(`/manga/${mangaId}/chapter/${chapter2Id}`);
+
+    const select = page.getByTestId('reader-chapter-select');
+    await expect(select).toBeVisible();
+
+    // The current chapter is preselected.
+    await expect(select).toHaveValue(chapter2Id);
+
+    // Each chapter rendered as "Ch. N — Title" (or "Ch. N" when title is null),
+    // in ascending number order — matching the prev/next sort.
+    const labels = await select.locator('option').allTextContents();
+    expect(labels.map((l) => l.trim())).toEqual([
+        'Ch. 1 — Somewhere, Not Here',
+        'Ch. 2',
+        'Ch. 3 — Sword Dance'
+    ]);
+});
+
+test('choosing a chapter from the select navigates to that chapter', async ({ page }) => {
+    await mockReaderApis(page);
+    await page.goto(`/manga/${mangaId}/chapter/${chapter1Id}`);
+
+    await expect(page.getByTestId('reader-chapter-select')).toHaveValue(chapter1Id);
+
+    await page.getByTestId('reader-chapter-select').selectOption(chapter3Id);
+
+    await expect(page).toHaveURL(
+        new RegExp(`/manga/${mangaId}/chapter/${chapter3Id}$`)
+    );
+    await expect(page.getByTestId('reader-chapter-select')).toHaveValue(chapter3Id);
+});

frontend/e2e/reader.spec.ts

@@ -120,7 +120,7 @@ test('manga overview shows title, cover, and a chapter list', async ({ page }) =
     await expect(page.getByTestId('manga-title')).toHaveText('Berserk');
     await expect(page.getByTestId('manga-author')).toContainText('Kentaro Miura');
     await expect(page.getByTestId('manga-cover')).toBeVisible();
-    await expect(page.getByTestId('chapter-list')).toContainText('Chapter 1');
+    await expect(page.getByTestId('chapter-list')).toContainText('The Brand');
     await expect(page.getByTestId('bookmark-signin')).toBeVisible();
 });
 

frontend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "mangalord-frontend",
-  "version": "0.49.1",
+  "version": "0.52.0",
   "private": true,
   "type": "module",
   "scripts": {

frontend/src/lib/api/admin.test.ts

@@ -14,7 +14,9 @@ import {
     createAdminUser,
     listAdminMangas,
     listAdminChapters,
-    getSystemStats
+    getSystemStats,
+    resyncManga,
+    resyncChapter
 } from './admin';
 
 function ok(body: unknown, status = 200): Response {
@@ -242,4 +244,88 @@ describe('admin api client', () => {
         const s = await getSystemStats();
         expect(s.disk).toBeNull();
     });
+
+    // ---- force resync ----
+
+    it('resyncManga POSTs to /v1/admin/mangas/{id}/resync and returns the envelope', async () => {
+        const resp = {
+            manga: {
+                id: 'm-1',
+                title: 'T',
+                status: 'ongoing',
+                alt_titles: [],
+                description: null,
+                cover_image_path: 'mangas/m-1/cover.jpg',
+                created_at: '2026-01-01T00:00:00Z',
+                updated_at: '2026-01-02T00:00:00Z',
+                authors: [],
+                genres: [],
+                tags: []
+            },
+            metadata_status: 'updated',
+            cover_fetched: true
+        };
+        fetchSpy.mockResolvedValueOnce(ok(resp));
+        const got = await resyncManga('m-1');
+        expect(got.metadata_status).toBe('updated');
+        expect(got.cover_fetched).toBe(true);
+        expect(got.manga.id).toBe('m-1');
+        const url = fetchSpy.mock.calls[0][0] as string;
+        expect(url).toMatch(/\/v1\/admin\/mangas\/m-1\/resync$/);
+        const init = fetchSpy.mock.calls[0][1] as RequestInit;
+        expect(init.method).toBe('POST');
+    });
+
+    it('resyncManga surfaces 503 service_unavailable when the daemon is off', async () => {
+        fetchSpy.mockResolvedValueOnce(
+            envelope(503, 'service_unavailable', 'crawler daemon is disabled')
+        );
+        await expect(resyncManga('m-1')).rejects.toMatchObject({
+            status: 503,
+            code: 'service_unavailable'
+        });
+    });
+
+    it('resyncChapter POSTs to /v1/admin/chapters/{id}/resync and returns the envelope', async () => {
+        const resp = {
+            chapter: {
+                id: 'c-1',
+                manga_id: 'm-1',
+                number: 1,
+                title: 'Foo',
+                page_count: 7,
+                created_at: '2026-01-01T00:00:00Z'
+            },
+            outcome: 'fetched',
+            pages: 7
+        };
+        fetchSpy.mockResolvedValueOnce(ok(resp));
+        const got = await resyncChapter('c-1');
+        expect(got.outcome).toBe('fetched');
+        expect(got.pages).toBe(7);
+        expect(got.chapter.page_count).toBe(7);
+        const url = fetchSpy.mock.calls[0][0] as string;
+        expect(url).toMatch(/\/v1\/admin\/chapters\/c-1\/resync$/);
+        const init = fetchSpy.mock.calls[0][1] as RequestInit;
+        expect(init.method).toBe('POST');
+    });
+
+    it('resyncChapter handles the "skipped" outcome envelope', async () => {
+        const resp = {
+            chapter: {
+                id: 'c-1',
+                manga_id: 'm-1',
+                number: 1,
+                title: null,
+                page_count: 7,
+                created_at: '2026-01-01T00:00:00Z'
+            },
+            outcome: 'skipped',
+            pages: null
+        };
+        fetchSpy.mockResolvedValueOnce(ok(resp));
+        const got = await resyncChapter('c-1');
+        expect(got.outcome).toBe('skipped');
+        expect(got.pages).toBeNull();
+    });
 });

frontend/src/lib/api/admin.ts

@@ -5,6 +5,8 @@
 
 import { request, type Page } from './client';
 import type { User } from './auth';
+import type { MangaDetail } from './mangas';
+import type { Chapter } from './chapters';
 
 // ---- users -----------------------------------------------------------------
 
@@ -176,3 +178,39 @@ export type SystemStats = {
 export async function getSystemStats(): Promise<SystemStats> {
     return request<SystemStats>('/v1/admin/system');
 }
+
+// ---- force resync ----------------------------------------------------------
+
+export type MangaResyncResponse = {
+    manga: MangaDetail;
+    metadata_status: 'new' | 'updated' | 'unchanged';
+    cover_fetched: boolean;
+};
+
+export type ChapterResyncResponse = {
+    chapter: Chapter;
+    outcome: 'fetched' | 'skipped';
+    /** Page count when `outcome === 'fetched'`; null when skipped. */
+    pages: number | null;
+};
+
+/** POST /v1/admin/mangas/:id/resync — refetches metadata + cover from
+ *  the manga's live crawler source. Long-running (one HTTP request per
+ *  Chromium nav + image download), so the UI should disable the trigger
+ *  and surface progress. */
+export async function resyncManga(id: string): Promise<MangaResyncResponse> {
+    return request<MangaResyncResponse>(
+        `/v1/admin/mangas/${encodeURIComponent(id)}/resync`,
+        { method: 'POST' }
+    );
+}
+
+/** POST /v1/admin/chapters/:id/resync — force-refetches a chapter's
+ *  pages even if `page_count > 0`. Same long-running caveat as
+ *  `resyncManga`. */
+export async function resyncChapter(id: string): Promise<ChapterResyncResponse> {
+    return request<ChapterResyncResponse>(
+        `/v1/admin/chapters/${encodeURIComponent(id)}/resync`,
+        { method: 'POST' }
+    );
+}

frontend/src/lib/api/chapters.test.ts

@@ -11,7 +11,8 @@ import {
     listChapters,
     getChapter,
     getChapterPages,
-    createChapter
+    createChapter,
+    chapterLabel
 } from './chapters';
 
 function ok(body: unknown): Response {
@@ -129,6 +130,18 @@ describe('chapters api client', () => {
         }
     });
 
+    describe('chapterLabel', () => {
+        it('returns the site title verbatim when present', () => {
+            expect(chapterLabel({ number: 7, title: 'Ch.7 : Official' })).toBe(
+                'Ch.7 : Official'
+            );
+        });
+
+        it('falls back to "Chapter {number}" when title is null', () => {
+            expect(chapterLabel({ number: 3, title: null })).toBe('Chapter 3');
+        });
+    });
+
     it('getChapterPages unwraps the {pages} envelope into the array', async () => {
         fetchSpy.mockResolvedValueOnce(
             ok({

frontend/src/lib/api/chapters.ts

@@ -14,6 +14,10 @@ export type ChaptersPage = {
     page: Page;
 };
 
+export function chapterLabel(c: Pick<Chapter, 'number' | 'title'>): string {
+    return c.title ?? `Chapter ${c.number}`;
+}
+
 export type ListOptions = {
     limit?: number;
     offset?: number;

frontend/src/routes/manga/[id]/+page.svelte

@@ -1,13 +1,16 @@
 <script lang="ts">
-    import { fileUrl } from '$lib/api/client';
+    import { fileUrl, ApiError } from '$lib/api/client';
     import { createBookmark, deleteBookmark, type Bookmark } from '$lib/api/bookmarks';
     import {
         attachTag,
         detachTag,
         type AuthorRef,
         type GenreRef,
+        type MangaDetail,
         type TagRef
     } from '$lib/api/mangas';
+    import { resyncManga } from '$lib/api/admin';
+    import { chapterLabel } from '$lib/api/chapters';
     import { listTags, type Tag } from '$lib/api/tags';
     import { session } from '$lib/session.svelte';
     import Chip from '$lib/components/Chip.svelte';
@@ -16,9 +19,15 @@
     import FolderPlus from '@lucide/svelte/icons/folder-plus';
     import Pencil from '@lucide/svelte/icons/pencil';
     import UploadCloud from '@lucide/svelte/icons/upload-cloud';
+    import RefreshCw from '@lucide/svelte/icons/refresh-cw';
 
     let { data } = $props();
-    const manga = $derived(data.manga);
+    // `manga` is locally overridable so a successful force resync can
+    // swap in the refreshed detail (new cover URL, refreshed status,
+    // etc.) without a router reload. Falls back to the server-loaded
+    // data otherwise.
+    let mangaOverride = $state<MangaDetail | null>(null);
+    const manga = $derived<MangaDetail>(mangaOverride ?? data.manga);
     const chapters = $derived(data.chapters);
     const readProgress = $derived(data.readProgress);
     /** Chapter row from the local chapters list when present (so we
@@ -37,6 +46,11 @@
         continueChapter?.number ?? readProgress?.chapter_number ?? null
     );
     const continueChapterTitle = $derived(continueChapter?.title ?? null);
+    const continueLabel = $derived(
+        continueChapterNumber != null
+            ? chapterLabel({ number: continueChapterNumber, title: continueChapterTitle })
+            : null
+    );
 
     const authors = $derived<AuthorRef[]>(manga.authors);
     const genres = $derived<GenreRef[]>(manga.genres);
@@ -171,6 +185,31 @@
     const statusLabel = $derived(manga.status === 'completed' ? 'Completed' : 'Ongoing');
 
     let collectionModalOpen = $state(false);
+
+    // ---- Admin force resync ----
+    let resyncBusy = $state(false);
+    let resyncMessage = $state<{ kind: 'ok' | 'err'; text: string } | null>(null);
+    async function forceResync() {
+        if (!session.user?.is_admin || resyncBusy) return;
+        resyncBusy = true;
+        resyncMessage = null;
+        try {
+            const r = await resyncManga(manga.id);
+            mangaOverride = r.manga;
+            const coverNote = r.cover_fetched
+                ? ' Cover re-downloaded.'
+                : ' Cover unchanged.';
+            resyncMessage = {
+                kind: 'ok',
+                text: `Metadata ${r.metadata_status}.${coverNote}`
+            };
+        } catch (e) {
+            const msg = e instanceof ApiError ? e.message : (e as Error).message;
+            resyncMessage = { kind: 'err', text: msg };
+        } finally {
+            resyncBusy = false;
+        }
+    }
 </script>
 
 <svelte:head>
@@ -344,7 +383,34 @@
                         <UploadCloud size={16} aria-hidden="true" />
                         <span>Upload chapter</span>
                     </a>
+                    {#if session.user.is_admin}
+                        <button
+                            type="button"
+                            class="action"
+                            onclick={forceResync}
+                            disabled={resyncBusy}
+                            title="Refetch metadata + cover from the crawler source"
+                            data-testid="force-resync-manga"
+                        >
+                            <RefreshCw
+                                size={16}
+                                aria-hidden="true"
+                                class={resyncBusy ? 'spin' : ''}
+                            />
+                            <span>{resyncBusy ? 'Resyncing…' : 'Force resync'}</span>
+                        </button>
+                    {/if}
                 </div>
+                {#if resyncMessage}
+                    <p
+                        class="resync-msg"
+                        class:err={resyncMessage.kind === 'err'}
+                        role="status"
+                        data-testid="force-resync-message"
+                    >
+                        {resyncMessage.text}
+                    </p>
+                {/if}
             {:else}
                 <a class="action" href="/login" data-testid="bookmark-signin">
                     Sign in to bookmark or collect
@@ -371,7 +437,7 @@
             >
                 <span class="continue-label">Continue reading</span>
                 <span class="continue-target">
-                    Chapter {continueChapterNumber}{#if continueChapterTitle}: {continueChapterTitle}{/if}
+                    {continueLabel}
                     {#if readProgress && readProgress.page > 1}
                         — page {readProgress.page}
                     {/if}
@@ -385,7 +451,7 @@
                 {#each chapters as c (c.id)}
                     <li>
                         <a href="/manga/{manga.id}/chapter/{c.id}">
-                            Chapter {c.number}{#if c.title}: {c.title}{/if}
+                            {chapterLabel(c)}
                         </a>
                         <span class="pages">({c.page_count} pages)</span>
                     </li>
@@ -586,6 +652,29 @@
         color: var(--text);
     }
 
+    .resync-msg {
+        margin-top: var(--space-2);
+        color: var(--text-muted);
+        font-size: var(--font-sm);
+    }
+
+    .resync-msg.err {
+        color: var(--danger);
+    }
+
+    :global(.spin) {
+        animation: spin 0.9s linear infinite;
+    }
+
+    @keyframes spin {
+        from {
+            transform: rotate(0deg);
+        }
+        to {
+            transform: rotate(360deg);
+        }
+    }
+
     .continue {
         display: flex;
         flex-direction: column;

frontend/src/routes/manga/[id]/chapter/[chapter_id]/+page.svelte

@@ -1,10 +1,12 @@
 <script lang="ts">
     import { onMount, onDestroy } from 'svelte';
-    import { goto } from '$app/navigation';
+    import { goto, invalidateAll } from '$app/navigation';
-    import { fileUrl } from '$lib/api/client';
+    import { fileUrl, ApiError } from '$lib/api/client';
     import { GAP_PX, type ReaderPageGap } from '$lib/api/preferences';
     import { preferences } from '$lib/preferences.svelte';
     import { updateReadProgress } from '$lib/api/read_progress';
+    import { chapterLabel } from '$lib/api/chapters';
+    import { resyncChapter } from '$lib/api/admin';
     import { readerFullscreen } from '$lib/reader-fullscreen.svelte';
     import { session } from '$lib/session.svelte';
     import ChevronLeft from '@lucide/svelte/icons/chevron-left';
@@ -15,6 +17,7 @@
     import ScrollText from '@lucide/svelte/icons/scroll-text';
     import Maximize2 from '@lucide/svelte/icons/maximize-2';
     import Minimize2 from '@lucide/svelte/icons/minimize-2';
+    import RefreshCw from '@lucide/svelte/icons/refresh-cw';
 
     let { data } = $props();
     const manga = $derived(data.manga);
@@ -26,28 +29,25 @@
     const gapPx = $derived(GAP_PX[preferences.readerPageGap]);
 
     const pageTitle = $derived(
-        chapter.title
+        `Mangalord | ${manga.title} · ${chapterLabel(chapter)}`
-            ? `Mangalord | ${manga.title} · Ch. ${chapter.number}: ${chapter.title}`
-            : `Mangalord | ${manga.title} · Ch. ${chapter.number}`
     );
 
     // Prev/next chapter computed from the chapter list. listChapters
-    // returns chapters in number ASC order; we still resolve via find
+    // returns chapters in display order (reversed source-site order, so
-    // rather than index because the current chapter's position may
+    // oldest first — see backend repo::chapter::list_for_manga), and
-    // not be `chapter.number - 1` (sparse numbering / chapter 0.5 /
+    // prev/next walks that order positionally. Resolving the current
-    // future skipped numbers).
+    // index via `find` rather than `chapter.number - 1` matters because
-    const sortedChapters = $derived(
+    // numbers aren't a reliable index: variants share numbers, non-
-        [...chapters].sort((a, b) => a.number - b.number)
+    // numeric entries pin to 0, and uploads can sparse-fill.
-    );
     const currentIdx = $derived(
-        sortedChapters.findIndex((c) => c.id === chapter.id)
+        chapters.findIndex((c) => c.id === chapter.id)
     );
     const prevChapter = $derived(
-        currentIdx > 0 ? sortedChapters[currentIdx - 1] : null
+        currentIdx > 0 ? chapters[currentIdx - 1] : null
     );
     const nextChapter = $derived(
-        currentIdx >= 0 && currentIdx < sortedChapters.length - 1
+        currentIdx >= 0 && currentIdx < chapters.length - 1
-            ? sortedChapters[currentIdx + 1]
+            ? chapters[currentIdx + 1]
             : null
     );
 
@@ -256,6 +256,36 @@
         if (typeof window !== 'undefined') window.removeEventListener('keydown', onKeydown);
     });
 
+    // ---- Admin force resync (current chapter) ----
+    let resyncBusy = $state(false);
+    let resyncMessage = $state<{ kind: 'ok' | 'err'; text: string } | null>(null);
+    async function forceResync() {
+        if (!session.user?.is_admin || resyncBusy) return;
+        resyncBusy = true;
+        resyncMessage = null;
+        try {
+            const r = await resyncChapter(chapter.id);
+            if (r.outcome === 'fetched') {
+                resyncMessage = {
+                    kind: 'ok',
+                    text: `Refetched ${r.pages} page${r.pages === 1 ? '' : 's'}. Reloading…`
+                };
+                // Re-run all loaders for this route so the reader picks
+                // up the freshly-downloaded pages. The page.ts loader
+                // doesn't `depends()` on anything explicitly, so
+                // invalidateAll is the right brush here.
+                await invalidateAll();
+            } else {
+                resyncMessage = { kind: 'ok', text: 'No new pages — source had nothing fresh.' };
+            }
+        } catch (e) {
+            const msg = e instanceof ApiError ? e.message : (e as Error).message;
+            resyncMessage = { kind: 'err', text: msg };
+        } finally {
+            resyncBusy = false;
+        }
+    }
+
     // ---- Reading progress tracking ----
     //
     // High-water mark seeded from the server: progress only ever moves
@@ -427,6 +457,27 @@
     </a>
 
     <div class="controls" role="group" aria-label="reader options">
+        <label class="chapter-field">
+            <span class="visually-hidden">Jump to chapter</span>
+            <select
+                class="chapter-select"
+                value={chapter.id}
+                onchange={(e) => {
+                    const target = (e.currentTarget as HTMLSelectElement).value;
+                    if (target && target !== chapter.id) {
+                        void goto(`/manga/${manga.id}/chapter/${target}`);
+                    }
+                }}
+                data-testid="reader-chapter-select"
+            >
+                {#each chapters as c (c.id)}
+                    <option value={c.id}>
+                        {chapterLabel(c)}
+                    </option>
+                {/each}
+            </select>
+        </label>
+
         <div class="mode-toggle" role="radiogroup" aria-label="layout">
             <button
                 type="button"
@@ -481,6 +532,23 @@
         {/if}
     </span>
 
+    {#if session.user?.is_admin}
+        <button
+            type="button"
+            class="reader-resync"
+            onclick={forceResync}
+            disabled={resyncBusy}
+            title={resyncMessage?.kind === 'err'
+                ? resyncMessage.text
+                : 'Force refetch this chapter from the crawler source'}
+            aria-label="Force resync chapter"
+            data-testid="force-resync-chapter"
+        >
+            <RefreshCw size={16} aria-hidden="true" class={resyncBusy ? 'spin' : ''} />
+            <span>{resyncBusy ? 'Resyncing…' : 'Force resync'}</span>
+        </button>
+    {/if}
+
     <button
         type="button"
         class="fullscreen-toggle"
@@ -494,6 +562,17 @@
     </button>
 </nav>
 
+{#if resyncMessage}
+    <p
+        class="resync-toast"
+        class:err={resyncMessage.kind === 'err'}
+        role="status"
+        data-testid="force-resync-message"
+    >
+        {resyncMessage.text}
+    </p>
+{/if}
+
 <!--
     Floating exit affordance — only rendered while focus mode is on.
     Lives in the top-right corner with a low resting opacity so it
@@ -604,7 +683,7 @@
             </span>
         </button>
         <span class="chapter-bar-current" aria-hidden="true">
-            Ch. {chapter.number}{#if chapter.title} — {chapter.title}{/if}
+            {chapterLabel(chapter)}
         </span>
         <button
             type="button"
@@ -741,7 +820,8 @@
         outline-offset: -2px;
     }
 
-    .gap-field select {
+    .gap-field select,
+    .chapter-select {
         height: 32px;
         padding: 0 var(--space-2);
         background: var(--surface);
@@ -751,6 +831,13 @@
         font-size: var(--font-sm);
     }
 
+    /* Cap the chapter dropdown's resting width so long titles don't
+       push the rest of the nav off-screen; the native control's
+       expanded menu still shows full option text on focus. */
+    .chapter-select {
+        max-width: 16rem;
+    }
+
     .visually-hidden {
         position: absolute;
         width: 1px;
@@ -911,7 +998,8 @@
     }
 
     /* ===== Focus-mode controls ===== */
-    .fullscreen-toggle {
+    .fullscreen-toggle,
+    .reader-resync {
         display: inline-flex;
         align-items: center;
         gap: var(--space-1);
@@ -925,12 +1013,52 @@
         font-size: var(--font-xs);
     }
 
-    .fullscreen-toggle:hover {
+    .fullscreen-toggle:hover,
+    .reader-resync:hover:not(:disabled) {
         background: var(--surface-elevated);
         color: var(--text);
         border-color: var(--primary);
     }
 
+    .reader-resync:disabled {
+        opacity: 0.7;
+        cursor: progress;
+    }
+
+    .resync-toast {
+        position: fixed;
+        top: calc(var(--app-header-h) + var(--reader-nav-h, 48px) + var(--space-2));
+        right: var(--space-3);
+        z-index: 11;
+        margin: 0;
+        padding: var(--space-2) var(--space-3);
+        max-width: min(420px, calc(100vw - 2 * var(--space-3)));
+        background: var(--surface);
+        color: var(--text);
+        border: 1px solid var(--primary);
+        border-radius: var(--radius-md);
+        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
+        font-size: var(--font-sm);
+    }
+
+    .resync-toast.err {
+        border-color: var(--danger);
+        color: var(--danger);
+    }
+
+    :global(.spin) {
+        animation: spin 0.9s linear infinite;
+    }
+
+    @keyframes spin {
+        from {
+            transform: rotate(0deg);
+        }
+        to {
+            transform: rotate(360deg);
+        }
+    }
+
     /* Small floating exit affordance — corner-pinned, low resting
        opacity so it doesn't sit on the chapter image too aggressively
        but is still findable without hover. */

frontend/src/routes/profile/history/+page.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
     import { fileUrl } from '$lib/api/client';
+    import { chapterLabel } from '$lib/api/chapters';
     import { clearReadProgress, type ReadProgressSummary } from '$lib/api/read_progress';
     import BookImage from '@lucide/svelte/icons/book-image';
     import Trash2 from '@lucide/svelte/icons/trash-2';
@@ -186,7 +187,7 @@
                                 <a href="/manga/{u.manga_id}" class="title">{u.manga_title}</a>
                                 <span class="target">
                                     <a href="/manga/{u.manga_id}/chapter/{u.chapter.id}">
-                                        Chapter {u.chapter.number}{#if u.chapter.title}: {u.chapter.title}{/if}
+                                        {chapterLabel(u.chapter)}
                                     </a>
                                     <span class="muted">({u.chapter.page_count} pages)</span>
                                 </span>