* fix(random-mix): honor keyword blocks and scope genre list to library
Keyword filter was gated behind the audiobook exclusion checkbox, so
blocked artists still appeared after Remix. Genre Mix now loads genres
via fetchGenreCatalog (scoped index / library filter) instead of raw
getGenres; show empty state when all tracks are filtered out.
* docs(changelog): credit zunoz on Psysonic Discord for PR #965
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.