feat(crawler): reconcile pass to enqueue mangas missing from the DB (0.85.0)

The interleaved metadata pass misses mangas to list drift (a title slips a
pagination slot during the slow detail walk). Add a reconcile pass: a cheap,
full, list-only walk (refs only, no detail visit, no early stop) that
set-diffs the walked keys against manga_sources and enqueues the strictly-
missing ones as SyncManga jobs. A set-diff is immune to drift — a manga only
has to appear somewhere in the list.

- Build the previously-dead SyncManga worker by extending RealChapterDispatcher
  to run the shared pipeline::process_manga_ref (fetch → upsert → cover →
  chapters), refactored out of run_metadata_pass so both paths stay in lockstep.
  The crawl worker now leases both sync_chapter_content and sync_manga
  (jobs::lease_kinds); both serialize on the single exclusive browser.
- SyncManga payload carries url + title so the worker can rebuild the ref and
  the dead-jobs/history UI can label a missing manga that has no manga row yet.
- "Missing" = strict NOT EXISTS (dropped rows count as present). Re-enqueue is
  skipped when a pending/running/dead SyncManga job already exists, so a gone
  manga (detail 404 → retries → dead) is left dead and not retried.
- New POST /v1/admin/crawler/reconcile (fire-and-forget, shares
  manual_pass_lock) + "Reconcile missing" admin button + Reconciling status
  phase streamed over SSE.
- dead-jobs/history queries surface payload title/url/key; tables fall back to
  them for sync_manga rows; both searches match the payload title.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/crawler/CrawlerControls.svelte

@@ -5,6 +5,7 @@
         status,
         busy,
         onRunPass,
+        onReconcile,
         onOpenRestart,
         onOpenSession,
         onClearExpired
@@ -12,6 +13,7 @@
         status: CrawlerStatus;
         busy: boolean;
         onRunPass: () => void;
+        onReconcile: () => void;
         onOpenRestart: () => void;
         onOpenSession: () => void;
         onClearExpired: () => void;
@@ -22,6 +24,12 @@
     <button onclick={onRunPass} disabled={busy || status.daemon !== 'running'}
         >Run metadata pass now</button
     >
+    <button
+        onclick={onReconcile}
+        disabled={busy || status.daemon !== 'running'}
+        title="Full list-only walk; enqueues mangas missing from the DB"
+        >Reconcile missing</button
+    >
     <button onclick={onOpenRestart} disabled={busy || status.daemon !== 'running'}
         >Restart browser</button
     >

frontend/src/lib/components/crawler/CrawlerHero.svelte

@@ -17,6 +17,8 @@
                 return `Fetching metadata · ${p.index}/${p.total ?? '?'} · ${p.title}`;
             case 'cover_backfill':
                 return `Backfilling covers · ${p.index + 1}/${p.total}`;
+            case 'reconciling':
+                return `Reconciling · walked ${p.walked} · enqueued ${p.enqueued}`;
             default: {
                 // Exhaustive default: if a new phase state ships
                 // without a label, TypeScript flags the missing case

frontend/src/lib/components/crawler/CrawlerHistoryTable.svelte

@@ -71,7 +71,8 @@
         await load();
     }
 
-    /** A human "Manga · Ch N · pP" target, or the source key / em-dash. */
+    /** A human "Manga · Ch N · pP" target. Falls back to the payload title
+     *  (sync_manga jobs with no manga row yet), then the source key. */
     function target(r: CrawlerHistoryRow): string {
         if (r.manga_title) {
             let s = r.manga_title;
@@ -79,7 +80,7 @@
             if (r.page_number != null) s += ` · p${r.page_number}`;
             return s;
         }
-        return r.source_key ?? '—';
+        return r.payload_title ?? r.source_key ?? '—';
     }
 
     function fmtAgo(iso: string): string {
@@ -172,7 +173,15 @@
                             <span class="badge state-{r.state}">{r.state}</span>
                         </td>
                         <td class="kind">{r.kind ?? '—'}</td>
-                        <td>{target(r)}</td>
+                        <td>
+                            {#if !r.manga_title && r.payload_title && r.source_url}
+                                <a href={r.source_url} target="_blank" rel="noreferrer noopener"
+                                    >{target(r)}</a
+                                >
+                            {:else}
+                                {target(r)}
+                            {/if}
+                        </td>
                         <td class="num">{fmtDuration(r.duration_ms)}</td>
                         <td>{r.attempts}/{r.max_attempts}</td>
                         <td title={new Date(r.updated_at).toLocaleString()}

frontend/src/lib/components/crawler/DeadJobsTable.svelte

@@ -56,7 +56,19 @@
                 {#each jobs as j (j.id)}
                     <tr>
                         <td>
-                            {j.manga_title ?? '(unknown)'}
+                            {#if j.manga_title}
+                                {j.manga_title}
+                            {:else if j.payload_title}
+                                {#if j.source_url}
+                                    <a href={j.source_url} target="_blank" rel="noreferrer noopener"
+                                        >{j.payload_title}</a
+                                    >
+                                {:else}
+                                    {j.payload_title}
+                                {/if}
+                            {:else}
+                                {j.source_key ?? '(unknown)'}
+                            {/if}
                             {#if j.chapter_number != null}· ch.{j.chapter_number}{/if}
                         </td>
                         <td>{j.attempts}/{j.max_attempts}</td>

frontend/src/lib/components/crawler/DeadJobsTable.svelte.test.ts

@@ -0,0 +1,69 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { render, screen, cleanup } from '@testing-library/svelte';
+import DeadJobsTable from './DeadJobsTable.svelte';
+import type { DeadJob } from '$lib/api/admin';
+
+afterEach(() => cleanup());
+
+function deadJob(overrides: Partial<DeadJob>): DeadJob {
+    return {
+        id: 'job-1',
+        kind: 'sync_chapter_content',
+        chapter_id: null,
+        manga_id: null,
+        manga_title: null,
+        chapter_number: null,
+        payload_title: null,
+        source_url: null,
+        source_key: null,
+        attempts: 5,
+        max_attempts: 5,
+        last_error: 'boom',
+        updated_at: '2026-06-16T00:00:00Z',
+        ...overrides
+    };
+}
+
+function baseProps(jobs: DeadJob[]) {
+    return {
+        jobs,
+        total: jobs.length,
+        page: 1,
+        totalPages: 1,
+        search: '',
+        busy: false,
+        onSearch: () => {},
+        onPageChange: () => {},
+        onRequeue: () => {},
+        onRequeueAll: () => {}
+    };
+}
+
+describe('DeadJobsTable', () => {
+    it('prefers manga_title when present', () => {
+        const jobs = [deadJob({ manga_title: 'Naruto', chapter_number: 700 })];
+        render(DeadJobsTable, { props: baseProps(jobs) });
+        expect(screen.getByText(/Naruto/)).toBeTruthy();
+    });
+
+    it('falls back to payload_title (linked to source_url) for a sync_manga job with no manga row', () => {
+        const jobs = [
+            deadJob({
+                kind: 'sync_manga',
+                manga_title: null,
+                payload_title: 'Ghost Manga',
+                source_url: 'http://x/manga/gone-1',
+                source_key: 'gone-1'
+            })
+        ];
+        render(DeadJobsTable, { props: baseProps(jobs) });
+        const link = screen.getByRole('link', { name: 'Ghost Manga' }) as HTMLAnchorElement;
+        expect(link.getAttribute('href')).toBe('http://x/manga/gone-1');
+    });
+
+    it('falls back to source_key when there is no title at all', () => {
+        const jobs = [deadJob({ kind: 'sync_manga', source_key: 'only-key' })];
+        render(DeadJobsTable, { props: baseProps(jobs) });
+        expect(screen.getByText('only-key')).toBeTruthy();
+    });
+});