fix(backend): split final UpdateAIJob + add goroutine recover() for AI job handlers

Split the single combined UpdateAIJob call at the end of each async
goroutine into two sequential calls (status first, payload second) so
that a failure writing the large results payload does not silently
prevent the job from being marked done. Added recover() to each
goroutine to catch and log panics. Affects chapter-names, description,
and image-gen handlers.

backend/internal/backend/handlers_image.go

@@ -559,6 +559,11 @@ func (s *Server) handleAdminImageGenAsync(w http.ResponseWriter, r *http.Request
 	go func() {
 		defer deregisterCancelJob(jobID)
 		defer jobCancel()
+		defer func() {
+			if r := recover(); r != nil {
+				logger.Error("admin: image-gen goroutine panic", "job_id", jobID, "recover", r)
+			}
+		}()
 
 		if jobCtx.Err() != nil {
 			_ = store.UpdateAIJob(context.Background(), jobID, map[string]any{
@@ -625,13 +630,19 @@ func (s *Server) handleAdminImageGenAsync(w http.ResponseWriter, r *http.Request
 			Guidance:    capturedReq.Guidance,
 		})
 
-		_ = store.UpdateAIJob(context.Background(), jobID, map[string]any{
-			"status":     string(domain.TaskStatusDone),
-			"items_done": 1,
+		if err := store.UpdateAIJob(context.Background(), jobID, map[string]any{
+			"status":      string(domain.TaskStatusDone),
+			"items_done":  1,
 			"items_total": 1,
-			"payload":    string(resultJSON),
-			"finished":   time.Now().Format(time.RFC3339),
-		})
+			"finished":    time.Now().Format(time.RFC3339),
+		}); err != nil {
+			logger.Error("admin: image-gen failed to mark job done", "job_id", jobID, "err", err)
+		}
+		if err := store.UpdateAIJob(context.Background(), jobID, map[string]any{
+			"payload": string(resultJSON),
+		}); err != nil {
+			logger.Error("admin: image-gen failed to write job payload", "job_id", jobID, "err", err)
+		}
 
 		logger.Info("admin: image-gen async done",
 			"job_id", jobID, "slug", capturedReq.Slug,

backend/internal/backend/handlers_textgen.go

@@ -516,6 +516,11 @@ func (s *Server) handleAdminTextGenChapterNamesAsync(w http.ResponseWriter, r *h
 	go func() {
 		defer deregisterCancelJob(jobID)
 		defer jobCancel()
+		defer func() {
+			if r := recover(); r != nil {
+				logger.Error("admin: text-gen chapter-names goroutine panic", "job_id", jobID, "recover", r)
+			}
+		}()
 
 		var allResults []proposedChapterTitle
 		chaptersDone := 0
@@ -574,12 +579,18 @@ func (s *Server) handleAdminTextGenChapterNamesAsync(w http.ResponseWriter, r *h
 		if jobCtx.Err() != nil {
 			status = domain.TaskStatusCancelled
 		}
-		_ = store.UpdateAIJob(context.Background(), jobID, map[string]any{
+		if err := store.UpdateAIJob(context.Background(), jobID, map[string]any{
 			"status":     string(status),
 			"items_done": chaptersDone,
 			"finished":   time.Now().Format(time.RFC3339),
-			"payload":    finalPayload,
-		})
+		}); err != nil {
+			logger.Error("admin: text-gen chapter-names failed to mark job done", "job_id", jobID, "err", err)
+		}
+		if err := store.UpdateAIJob(context.Background(), jobID, map[string]any{
+			"payload": finalPayload,
+		}); err != nil {
+			logger.Error("admin: text-gen chapter-names failed to write job payload", "job_id", jobID, "err", err)
+		}
 		logger.Info("admin: text-gen chapter-names async done",
 			"job_id", jobID, "slug", capturedSlug,
 			"results", len(allResults), "status", string(status))
@@ -902,6 +913,11 @@ func (s *Server) handleAdminTextGenDescriptionAsync(w http.ResponseWriter, r *ht
 	go func() {
 		defer deregisterCancelJob(jobID)
 		defer jobCancel()
+		defer func() {
+			if r := recover(); r != nil {
+				logger.Error("admin: text-gen description goroutine panic", "job_id", jobID, "recover", r)
+			}
+		}()
 
 		if jobCtx.Err() != nil {
 			_ = store.UpdateAIJob(context.Background(), jobID, map[string]any{
@@ -955,13 +971,19 @@ func (s *Server) handleAdminTextGenDescriptionAsync(w http.ResponseWriter, r *ht
 			NewDescription: strings.TrimSpace(newDesc),
 		})
 
-		_ = store.UpdateAIJob(context.Background(), jobID, map[string]any{
+		if err := store.UpdateAIJob(context.Background(), jobID, map[string]any{
 			"status":      string(domain.TaskStatusDone),
 			"items_done":  1,
 			"items_total": 1,
-			"payload":     string(resultJSON),
 			"finished":    time.Now().Format(time.RFC3339),
-		})
+		}); err != nil {
+			logger.Error("admin: text-gen description failed to mark job done", "job_id", jobID, "err", err)
+		}
+		if err := store.UpdateAIJob(context.Background(), jobID, map[string]any{
+			"payload": string(resultJSON),
+		}); err != nil {
+			logger.Error("admin: text-gen description failed to write job payload", "job_id", jobID, "err", err)
+		}
 		logger.Info("admin: text-gen description async done", "job_id", jobID, "slug", capturedMeta.Slug)
 	}()
 

backend/internal/cfai/text.go

@@ -237,14 +237,18 @@ func (c *textGenHTTPClient) Generate(ctx context.Context, req TextRequest) (stri
 	if err := json.Unmarshal(wrapper.Result.Response, &text); err == nil {
 		return text, nil
 	}
-	// Fall back: array of objects with a "generated_text" field.
+	// Fall back: array of objects with a "generated_text" field
+	// (older CF AI models return [{"generated_text":"..."}]).
 	var arr []struct {
 		GeneratedText string `json:"generated_text"`
 	}
-	if err := json.Unmarshal(wrapper.Result.Response, &arr); err == nil && len(arr) > 0 {
+	if err := json.Unmarshal(wrapper.Result.Response, &arr); err == nil && len(arr) > 0 && arr[0].GeneratedText != "" {
 		return arr[0].GeneratedText, nil
 	}
-	return "", fmt.Errorf("cfai/text: model %s: unrecognised response shape: %s", req.Model, wrapper.Result.Response)
+	// Final fallback: model returned the result directly as a JSON value
+	// (e.g. Llama 4 Scout returns [{"number":1,"title":"..."},...] directly).
+	// Return the raw JSON bytes as a string so callers can parse it themselves.
+	return string(wrapper.Result.Response), nil
 }
 
 // Models returns all supported text generation model metadata.

ui/src/routes/api/scrape/task/[id]/+server.ts

@@ -15,5 +15,5 @@ export const GET: RequestHandler = async ({ params }) => {
 	const task = await getScrapingTask(id).catch(() => null);
 	if (!task) throw error(404, 'Task not found');
 
-	return json({ id: task.id, status: task.status, error_message: task.error_message ?? '' });
+	return json({ id: task.id, status: task.status, chapters_scraped: task.chapters_scraped ?? 0, error_message: task.error_message ?? '' });
 };

ui/src/routes/books/[slug]/chapters/[n]/+page.server.ts

@@ -167,17 +167,24 @@ export const load: PageServerLoad = async ({ params, url, locals }) => {
 
 	// ── Original content path ──────────────────────────────────────────────
 	let html = '';
+	let contentMissing = false;
 	try {
 		const res = await backendFetch(`/api/chapter-markdown/${encodeURIComponent(slug)}/${n}`);
 		if (!res.ok) {
 			log.error('chapter', 'chapter-markdown returned error', { slug, n, status: res.status });
-			error(res.status === 404 ? 404 : 502, res.status === 404 ? `Chapter ${n} not found` : 'Could not fetch chapter content');
+			if (res.status === 404) {
+				// Content file missing from storage — render the page shell with an
+				// empty body so admins can trigger a re-scrape from the page itself.
+				contentMissing = true;
+			} else {
+				error(502, 'Could not fetch chapter content');
+			}
+		} else {
+			const markdown = await res.text();
+			html = await marked(markdown);
 		}
-		const markdown = await res.text();
-		html = await marked(markdown);
 	} catch (e) {
 		if (e instanceof Error && 'status' in e) throw e;
-		// Don't hard-fail — show empty content with error message
 		log.error('chapter', 'failed to fetch chapter content', { slug, n, err: String(e) });
 		error(502, 'Could not fetch chapter content');
 	}
@@ -202,9 +209,10 @@ export const load: PageServerLoad = async ({ params, url, locals }) => {
 	const nextChapter = chapters.find((c) => c.number === n + 1) ?? null;
 
 	return {
-		book: { slug: book.slug, title: book.title, cover: book.cover ?? '' },
+		book: { slug: book.slug, title: book.title, cover: book.cover ?? '', source_url: book.source_url ?? '' },
 		chapter: chapterIdx,
 		html,
+		contentMissing,
 		voices,
 		prev: prevChapter ? prevChapter.number : null,
 		next: nextChapter ? nextChapter.number : null,
@@ -214,6 +222,7 @@ export const load: PageServerLoad = async ({ params, url, locals }) => {
 		lang: useTranslation ? lang : '',
 		translationStatus,
 		isPro: locals.isPro,
+		isAdmin: locals.user?.role === 'admin',
 		chapterImageUrl,
 		audioReady,
 		availableVoice

ui/src/routes/books/[slug]/chapters/[n]/+page.svelte

@@ -374,7 +374,9 @@
 		}
 
 		// If the normal path returned no content, fall back to live preview scrape
-		if (!data.isPreview && !data.html) {
+		// (but only when contentMissing is false — if the file is genuinely absent
+		//  from storage the preview scrape won't help either and admins can re-queue)
+		if (!data.isPreview && !data.html && !data.contentMissing) {
 			fetchingContent = true;
 			(async () => {
 				try {
@@ -406,6 +408,62 @@
 		html ? (html.replace(/<[^>]*>/g, '').match(/\S+/g)?.length ?? 0) : 0
 	);
 
+	// ── Admin chapter tools ────────────────────────────────────────────────────
+	let adminOpen      = $state(false);
+	let scrapeStatus   = $state<'idle' | 'busy' | 'queued' | 'error'>('idle');
+	let scrapeTaskId   = $state('');
+	let scrapeProgress = $state('');
+	let pollTimer      = 0;
+
+	async function scrapeThisChapter() {
+		if (scrapeStatus === 'busy' || !data.book.source_url) return;
+		scrapeStatus = 'busy';
+		scrapeProgress = '';
+		try {
+			const res = await fetch('/api/scrape/range', {
+				method: 'POST',
+				headers: { 'Content-Type': 'application/json' },
+				body: JSON.stringify({ url: data.book.source_url, from: data.chapter.number, to: data.chapter.number })
+			});
+			const d = await res.json().catch(() => ({}));
+			if (res.ok) {
+				scrapeStatus = 'queued';
+				scrapeTaskId = d.task_id ?? '';
+				if (scrapeTaskId) startPollTask(scrapeTaskId);
+			} else if (res.status === 409) {
+				scrapeStatus = 'error';
+				scrapeProgress = 'A scrape job is already running — try again shortly.';
+			} else {
+				scrapeStatus = 'error';
+				scrapeProgress = d.message ?? `Error ${res.status}`;
+			}
+		} catch (e) {
+			scrapeStatus = 'error';
+			scrapeProgress = String(e);
+		}
+	}
+
+	function startPollTask(id: string) {
+		clearTimeout(pollTimer);
+		pollTimer = setTimeout(async () => {
+			try {
+				const res = await fetch(`/api/scrape/task/${id}`);
+				if (!res.ok) return;
+				const d = await res.json() as { status: string; chapters_scraped?: number; error_message?: string };
+				if (d.status === 'done') {
+					scrapeProgress = `Done — ${d.chapters_scraped ?? 0} chapter(s) scraped. Reload to see content.`;
+					scrapeStatus = 'queued';
+				} else if (d.status === 'failed') {
+					scrapeProgress = `Failed: ${d.error_message ?? 'unknown error'}`;
+					scrapeStatus = 'error';
+				} else {
+					scrapeProgress = `Status: ${d.status}${d.chapters_scraped ? ` (${d.chapters_scraped} done)` : ''}`;
+					startPollTask(id); // keep polling
+				}
+			} catch { /* ignore */ }
+		}, 3000) as unknown as number;
+	}
+
 	// Strip scraper artifacts from chapter titles:
 	//  - Leading digit(s) prefixed before "Chapter" (e.g. "6Chapter 6 : ...")
 	//  - Everything after the first newline (often includes a scraped date)
@@ -717,8 +775,115 @@
 		{m.reader_fetching_chapter()}
 	</div>
 {:else if !html}
-	<div class="text-(--color-muted) text-center py-16">
-		<p>{fetchError || m.reader_audio_error()}</p>
+	<!-- ── Content unavailable ─────────────────────────────────────────── -->
+	<div class="mt-8 rounded-xl border border-(--color-border) bg-(--color-surface-2) overflow-hidden">
+		<!-- Banner — visible to all users -->
+		<div class="flex items-start gap-4 p-6">
+			<div class="w-10 h-10 rounded-full bg-(--color-surface-3) flex items-center justify-center shrink-0 mt-0.5">
+				<svg class="w-5 h-5 text-(--color-muted)" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+					<path stroke-linecap="round" stroke-linejoin="round" stroke-width="1.5" d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"/>
+				</svg>
+			</div>
+			<div>
+				<p class="font-semibold text-(--color-text) mb-1">Chapter content not available</p>
+				<p class="text-sm text-(--color-muted)">
+					{#if data.contentMissing}
+						This chapter exists in the index but its content hasn't been stored yet.
+						{#if !data.isAdmin}It should appear soon — try refreshing in a few minutes.{/if}
+					{:else}
+						{fetchError || 'Could not load this chapter. Please try again.'}
+					{/if}
+				</p>
+			</div>
+		</div>
+
+		<!-- Admin toolbar — only visible to admins -->
+		{#if data.isAdmin}
+			<div class="border-t border-(--color-border)">
+				<button
+					type="button"
+					onclick={() => (adminOpen = !adminOpen)}
+					class="w-full flex items-center gap-2 px-5 py-3 text-xs font-semibold text-(--color-muted) hover:text-(--color-text) hover:bg-(--color-surface-3)/40 transition-colors text-left"
+				>
+					<svg class="w-3.5 h-3.5 shrink-0 text-(--color-brand)" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+						<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M10.325 4.317c.426-1.756 2.924-1.756 3.35 0a1.724 1.724 0 002.573 1.066c1.543-.94 3.31.826 2.37 2.37a1.724 1.724 0 001.065 2.572c1.756.426 1.756 2.924 0 3.35a1.724 1.724 0 00-1.066 2.573c.94 1.543-.826 3.31-2.37 2.37a1.724 1.724 0 00-2.572 1.065c-.426 1.756-2.924 1.756-3.35 0a1.724 1.724 0 00-2.573-1.066c-1.543.94-3.31-.826-2.37-2.37a1.724 1.724 0 00-1.065-2.572c-1.756-.426-1.756-2.924 0-3.35a1.724 1.724 0 001.066-2.573c-.94-1.543.826-3.31 2.37-2.37.996.608 2.296.07 2.572-1.065z"/>
+						<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z"/>
+					</svg>
+					Admin Tools
+					<svg class="w-3 h-3 ml-auto transition-transform {adminOpen ? 'rotate-180' : ''}" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+						<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7"/>
+					</svg>
+				</button>
+
+				{#if adminOpen}
+				<div class="px-5 pb-5 flex flex-col gap-4 border-t border-(--color-border)">
+
+					<!-- Source URL info -->
+					{#if data.book.source_url}
+						<div class="mt-3">
+							<p class="text-xs text-(--color-muted) mb-1">Source URL</p>
+							<a href={data.book.source_url} target="_blank" rel="noopener noreferrer"
+								class="text-xs text-(--color-brand) hover:underline break-all">
+								{data.book.source_url}
+							</a>
+						</div>
+					{/if}
+
+					<!-- Scrape this chapter -->
+					<div class="flex flex-col gap-2">
+						<p class="text-xs font-medium text-(--color-muted) uppercase tracking-wide">Scrape Chapter {data.chapter.number}</p>
+						<div class="flex items-center gap-2 flex-wrap">
+							<button
+								type="button"
+								onclick={scrapeThisChapter}
+								disabled={scrapeStatus === 'busy' || !data.book.source_url}
+								class="inline-flex items-center gap-1.5 px-3 py-1.5 rounded-lg bg-(--color-brand) text-(--color-surface) font-semibold text-xs hover:bg-(--color-brand-dim) disabled:opacity-50 transition-colors"
+							>
+								{#if scrapeStatus === 'busy'}
+									<svg class="w-3.5 h-3.5 animate-spin" fill="none" viewBox="0 0 24 24">
+										<circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
+										<path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z"></path>
+									</svg>
+									Scraping…
+								{:else}
+									<svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+										<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15"/>
+									</svg>
+									Re-scrape ch.{data.chapter.number}
+								{/if}
+							</button>
+							{#if !data.book.source_url}
+								<span class="text-xs text-(--color-muted)">No source URL on this book.</span>
+							{/if}
+						</div>
+						{#if scrapeProgress}
+							<p class="text-xs {scrapeStatus === 'error' ? 'text-red-400' : 'text-green-400'}">{scrapeProgress}</p>
+						{:else if scrapeStatus === 'queued'}
+							<p class="text-xs text-(--color-muted)">Queued — polling for completion…</p>
+						{/if}
+					</div>
+
+					<!-- Quick links -->
+					<div class="flex flex-col gap-1.5">
+						<p class="text-xs font-medium text-(--color-muted) uppercase tracking-wide">Quick links</p>
+						<div class="flex flex-wrap gap-2">
+							<a href="/admin/scrape" class="text-xs px-2.5 py-1 rounded-md bg-(--color-surface-3) text-(--color-muted) hover:text-(--color-text) transition-colors">
+								Scrape dashboard
+							</a>
+							<a href="/books/{data.book.slug}" class="text-xs px-2.5 py-1 rounded-md bg-(--color-surface-3) text-(--color-muted) hover:text-(--color-text) transition-colors">
+								Book page
+							</a>
+							<a href="https://pb.libnovel.cc/_/" target="_blank" rel="noopener noreferrer"
+								class="text-xs px-2.5 py-1 rounded-md bg-(--color-surface-3) text-(--color-muted) hover:text-(--color-text) transition-colors">
+								PocketBase ↗
+							</a>
+						</div>
+					</div>
+
+				</div>
+				{/if}
+			</div>
+		{/if}
 	</div>
 {:else}
 	<!-- Chapter illustration hero (if generated, hidden in focus mode) -->