feat: in-reader settings, more like this, reading history, audio filter, feed page

- Add floating gear button + theme/font/size drawer in chapter reader
- Add 'More like this' horizontal scroll row on book detail page
- Add reading history tab on profile page (chronological progress timeline)
- Add audio-available badge + filter toggle on catalogue (GET /api/audio/slugs)
- Fix discover card entry animation pop (split entry vs snap-back cubic-bezier)
- Add dedicated /feed page showing books followed users are reading
- Add Feed nav link (desktop + mobile) in all 5 locales

ui/messages/id.json

@@ -3,6 +3,7 @@
 
   "nav_library": "Perpustakaan",
   "nav_catalogue": "Katalog",
+  "nav_feed": "Umpan",
   "nav_feedback": "Masukan",
   "nav_admin": "Admin",
   "nav_profile": "Profil",
@@ -418,5 +419,16 @@
   "profile_text_size_sm": "Kecil",
   "profile_text_size_md": "Normal",
   "profile_text_size_lg": "Besar",
-  "profile_text_size_xl": "Sangat Besar"
+  "profile_text_size_xl": "Sangat Besar",
+
+  "feed_page_title": "Umpan — LibNovel",
+  "feed_heading": "Umpan Ikutan",
+  "feed_subheading": "Buku yang sedang dibaca oleh pengguna yang Anda ikuti",
+  "feed_empty_heading": "Belum ada apa-apa",
+  "feed_empty_body": "Ikuti pembaca lain untuk melihat apa yang mereka baca.",
+  "feed_not_logged_in": "Masuk untuk melihat umpan Anda.",
+  "feed_reader_label": "membaca",
+  "feed_chapters_label": "{n} bab",
+  "feed_browse_cta": "Jelajahi katalog",
+  "feed_find_users_cta": "Temukan pembaca"
 }