Phase 2 of the mobile redesign: the catalog at `/` adapts to phone
viewports without disrupting the desktop layout. The same filter form
renders inline on desktop and inside a bottom sheet on mobile, and a
dedicated sort sheet replaces the inline `<select>` below 640px.
- MangaCard gains optional `unreadCount` and `progress` props that
render a top-right pill badge and a bottom progress overlay on the
cover. Both are no-ops when omitted, so existing callers don't
change. Counts past 99 cap at "99+".
- The filter form body is extracted into a Svelte 5 snippet and
rendered conditionally — inline desktop panel OR mobile sheet, never
both — so no testid is duplicated and the focus trap can't double-
fire. A matchMedia listener tracks the 640px breakpoint and drives
the snippet target.
- Mobile catalog adds: Filter / Sort chip buttons, an always-visible
active-filter chip row with per-facet remove buttons, full-width
search, and a 2-column grid.
- Auto-expanding the filter panel from URL params is now desktop-only
— on mobile the active-filter chips signal applied facets without
hiding the catalog under a scrim on first paint.
- Vitest suite covers MangaCard badge / overlay behavior including
clamp / hide edge cases. Playwright spec covers the mobile filter +
sort sheet flow at 390px viewport, with a hydration gate to keep
click dispatch from racing the SSR'd-but-not-yet-reactive button.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>