feat(frontend): mobile manga detail with hero + sticky CTA (0.58.0)

Phase 3 of the mobile redesign: the manga detail page gets a mobile-
native chrome — blurred-cover hero with a transparent app bar overlay,
secondary actions in an overflow Sheet, a 3-line description clamp
with Read more, and a sticky bottom CTA whose wording reflects read
progress. Desktop layout is untouched.

- /manga/[id] joins the layout's HIDE_MOBILE_CHROME route set so the
  global AppBar and BottomNav step aside for the page-specific hero
  chrome. A new `html[data-mobile-full-bleed]` opt-in zeroes main's
  mobile top padding without touching horizontal/bottom gutters.
- The hero block (mobile-only via CSS) renders a blurred cover
  backdrop, a transparent app bar (back / bookmark / overflow ⋯), and
  a sharp cover thumbnail beside the title, authors, and status. The
  bookmark icon swaps between Bookmark and BookmarkCheck based on the
  current bookmark state — reusing the existing toggleBookmark flow.
- Secondary actions (Add to collection / Edit / Upload chapter /
  Force resync) move into an overflow Sheet opened from the ⋯
  button. The desktop action-row stays.
- Description gets a `.clamped` modifier (-webkit-line-clamp: 3) and
  a Read more toggle on mobile, gated by a >200-char heuristic so
  short blurbs don't render a dangling button. Desktop shows the
  full description as before.
- Sticky bottom CTA bar reads "Continue {chapterLabel}" when
  data.readProgress has a chapter_id, "Read first chapter" when
  the manga has chapters but no progress, and hides otherwise. The
  bar honors env(safe-area-inset-bottom) so it sits above the iOS
  home indicator.
- New Playwright spec covers the CTA wording state machine
  (no-progress → Read first chapter, has-progress → Continue),
  Read more expand/collapse, overflow sheet contents, and a desktop
  regression for the unchanged action-row.

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

frontend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "mangalord-frontend",
-  "version": "0.57.0",
+  "version": "0.58.0",
   "private": true,
   "type": "module",
   "scripts": {