Pull pure helpers, the contributors/maintainers data list and the
tab type/search index out of `Settings.tsx` so the main component
only has tab-section render logic + the orchestrating state left:
- `utils/audioDeviceLabels.ts` — five ALSA-device label helpers
(formatAudioDeviceLabel + duplicate-disambiguation + sort +
select-option builder).
- `utils/formatBytes.ts` — formatBytes + snapHotCacheMb.
- `components/settings/LoudnessLufsButtonGroup.tsx` — small chip
group used by the audio tab.
- `components/settings/settingsTabs.ts` — `Tab` type + legacy alias
map + `resolveTab` + `SearchIndexEntry` + `SETTINGS_INDEX` + the
`matchScore` substring-with-fuzzy-fallback scorer.
- `config/settingsCredits.ts` — `CONTRIBUTORS` (~270 LOC of static
contributor history) + `MAINTAINERS`.
Pure code-move. Settings.tsx: 3552 → 3037 LOC (−515). Settings/G
journey now 5298 → 3037 LOC (~43% reduction).