feat: admin UX overhaul — status filters, retry/cancel, mobile cards, i18n, shelf pre-populate

- Admin layout: SVG icons, active highlight, divider between nav sections
- Scrape page: status filter pills with counts, text + status combined search
- Audio page: status filter pills, cancel jobs, retry failed jobs, mobile cards for cache tab
- Translation page: status filter pills (incl. cancelled), cancel + retry jobs, mobile cancel/retry cards, i18n for all labels
- AI Jobs page: fix concurrent cancel (Set instead of single slot), per-job cancel errors inline, full mobile card layout, i18n title/heading
- Text-gen page: tagline editable input + copy, warnings copy, i18n title/heading
- Book page: chapter cover Save button, audio monitor link, currentShelf pre-populated from server
- pocketbase.ts: add getBookShelf(), shelf field on UserLibraryEntry
- New API route: POST /api/admin/translation/bulk (proxy for translation retry)
- i18n: 15 new admin_translation_*, admin_ai_jobs_*, admin_text_gen_* keys across all 5 locales

ui/messages/en.json

@@ -478,5 +478,20 @@
   "feed_reader_label": "reading",
   "feed_chapters_label": "{n} chapters",
   "feed_browse_cta": "Browse catalogue",
-  "feed_find_users_cta": "Discover readers"
+  "feed_find_users_cta": "Discover readers",
+
+  "admin_translation_page_title": "Translation \u2014 Admin",
+  "admin_translation_heading": "Machine Translation",
+  "admin_translation_tab_enqueue": "Enqueue",
+  "admin_translation_tab_jobs": "Jobs",
+  "admin_translation_filter_placeholder": "Filter by slug, lang, or status\u2026",
+  "admin_translation_no_matching": "No matching jobs.",
+  "admin_translation_no_jobs": "No translation jobs yet.",
+
+  "admin_ai_jobs_page_title": "AI Jobs \u2014 Admin",
+  "admin_ai_jobs_heading": "AI Jobs",
+  "admin_ai_jobs_subheading": "Background AI generation tasks",
+
+  "admin_text_gen_page_title": "Text Gen \u2014 Admin",
+  "admin_text_gen_heading": "Text Generation"
 }

ui/messages/fr.json

@@ -476,5 +476,20 @@
   "feed_browse_cta": "Parcourir le catalogue",
   "feed_find_users_cta": "Trouver des lecteurs",
   "admin_nav_gitea": "Gitea",
-  "admin_nav_grafana": "Grafana"
+  "admin_nav_grafana": "Grafana",
+
+  "admin_translation_page_title": "Translation \u2014 Admin",
+  "admin_translation_heading": "Machine Translation",
+  "admin_translation_tab_enqueue": "Enqueue",
+  "admin_translation_tab_jobs": "Jobs",
+  "admin_translation_filter_placeholder": "Filter by slug, lang, or status\u2026",
+  "admin_translation_no_matching": "No matching jobs.",
+  "admin_translation_no_jobs": "No translation jobs yet.",
+
+  "admin_ai_jobs_page_title": "AI Jobs \u2014 Admin",
+  "admin_ai_jobs_heading": "AI Jobs",
+  "admin_ai_jobs_subheading": "Background AI generation tasks",
+
+  "admin_text_gen_page_title": "Text Gen \u2014 Admin",
+  "admin_text_gen_heading": "Text Generation"
 }

ui/messages/id.json

@@ -476,5 +476,20 @@
   "feed_browse_cta": "Jelajahi katalog",
   "feed_find_users_cta": "Temukan pembaca",
   "admin_nav_gitea": "Gitea",
-  "admin_nav_grafana": "Grafana"
+  "admin_nav_grafana": "Grafana",
+
+  "admin_translation_page_title": "Translation \u2014 Admin",
+  "admin_translation_heading": "Machine Translation",
+  "admin_translation_tab_enqueue": "Enqueue",
+  "admin_translation_tab_jobs": "Jobs",
+  "admin_translation_filter_placeholder": "Filter by slug, lang, or status\u2026",
+  "admin_translation_no_matching": "No matching jobs.",
+  "admin_translation_no_jobs": "No translation jobs yet.",
+
+  "admin_ai_jobs_page_title": "AI Jobs \u2014 Admin",
+  "admin_ai_jobs_heading": "AI Jobs",
+  "admin_ai_jobs_subheading": "Background AI generation tasks",
+
+  "admin_text_gen_page_title": "Text Gen \u2014 Admin",
+  "admin_text_gen_heading": "Text Generation"
 }

ui/messages/pt.json

@@ -476,5 +476,20 @@
   "feed_browse_cta": "Ver catálogo",
   "feed_find_users_cta": "Encontrar leitores",
   "admin_nav_gitea": "Gitea",
-  "admin_nav_grafana": "Grafana"
+  "admin_nav_grafana": "Grafana",
+
+  "admin_translation_page_title": "Translation \u2014 Admin",
+  "admin_translation_heading": "Machine Translation",
+  "admin_translation_tab_enqueue": "Enqueue",
+  "admin_translation_tab_jobs": "Jobs",
+  "admin_translation_filter_placeholder": "Filter by slug, lang, or status\u2026",
+  "admin_translation_no_matching": "No matching jobs.",
+  "admin_translation_no_jobs": "No translation jobs yet.",
+
+  "admin_ai_jobs_page_title": "AI Jobs \u2014 Admin",
+  "admin_ai_jobs_heading": "AI Jobs",
+  "admin_ai_jobs_subheading": "Background AI generation tasks",
+
+  "admin_text_gen_page_title": "Text Gen \u2014 Admin",
+  "admin_text_gen_heading": "Text Generation"
 }

ui/messages/ru.json

@@ -476,5 +476,20 @@
   "feed_browse_cta": "Каталог",
   "feed_find_users_cta": "Найти читателей",
   "admin_nav_gitea": "Gitea",
-  "admin_nav_grafana": "Grafana"
+  "admin_nav_grafana": "Grafana",
+
+  "admin_translation_page_title": "Translation \u2014 Admin",
+  "admin_translation_heading": "Machine Translation",
+  "admin_translation_tab_enqueue": "Enqueue",
+  "admin_translation_tab_jobs": "Jobs",
+  "admin_translation_filter_placeholder": "Filter by slug, lang, or status\u2026",
+  "admin_translation_no_matching": "No matching jobs.",
+  "admin_translation_no_jobs": "No translation jobs yet.",
+
+  "admin_ai_jobs_page_title": "AI Jobs \u2014 Admin",
+  "admin_ai_jobs_heading": "AI Jobs",
+  "admin_ai_jobs_subheading": "Background AI generation tasks",
+
+  "admin_text_gen_page_title": "Text Gen \u2014 Admin",
+  "admin_text_gen_heading": "Text Generation"
 }