* feat(hero): prev / next arrows on the Mainstage featured strip
Adds left and right chevron buttons over the featured-album hero so a
single click flips to the previous / next album. Hitting the 8 px dot
indicators was awkward and often opened the underlying album by
mistake; the arrows give a generous 44 px touch target on each edge.
- New `goPrev` / `goNext` callbacks wrap with modulo, restart the
auto-advance timer on click (same pattern the old dot handler used).
- Buttons live in a new `.hero-nav` flex wrapper with `inset: 0` and
`justify-content: space-between`, so they pin to the hero's left and
right edges regardless of theme padding. `pointer-events: none` on
the wrapper + `auto` on the buttons keeps the rest of the hero
click-through (navigate to album).
- Dots are now decorative spans, not buttons — `pointer-events: none`,
no hover state, no `onClick`. Clicking near a dot used to navigate
to the album because the dot was too small to land on.
- i18n: `previousAlbum` / `nextAlbum` keys in all 9 locales.
Reported by zunoz on Discord.
* docs(changelog): note Mainstage hero prev / next arrows (#735)
Each src/locales/<lang>.ts (~1800 LOC) becomes a folder src/locales/<lang>/
with one module per i18n namespace (44 each) plus an index.ts barrel that
reassembles <lang>Translation in the original key order.
Mechanical, script-driven split with a JSON round-trip check: every
locale object is byte-identical to its pre-split form. i18n.ts is
unchanged — './locales/<lang>' now resolves to the folder index.
The per-namespace settings.ts files land ~440-460 LOC; a single i18n
namespace is the natural, non-arbitrary split unit for a flat string
table, so they are intentionally left whole.