fix: initialize model language filter from user preference (#1265)

[ChristophNoetel]

Summary

• The Models settings page always showed all models regardless of the user's selected transcription language
• Now initializes the language filter dropdown from the user's selected_language setting
• When selected_language is "auto" or unset, defaults to "All Languages" (preserves current behavior)

Closes #1265

Details

The ModelsSettings component had a local languageFilter state hardcoded to "all". This meant every time a user opened Settings > Models, they'd see all models in all languages -- even if they'd configured English-only transcription.

The fix reads selected_language from AppSettings via the existing useSettings hook (same pattern as LanguageSelector.tsx) and uses it as the initial filter value. The dropdown still allows browsing models in other languages by manually changing the filter.

Mapping: "auto" / undefined -> "all" (show everything); "en", "de", etc. -> filter directly.

Test plan

• Set language to "English" in Settings > General, then open Settings > Models -- should show only English-capable models
• Set language to "Auto Detect" -- Models page should show all models (no filter)
• With language set to "German": Models page pre-filters to German, but dropdown can be changed to "All Languages" to browse everything
• Fresh install (no language set): Models page shows all models

[ChristophNoetel]

Closing this — the underlying issue #1265 was resolved as not-a-bug (Breeze ASR does support English, per @cjpais), so initializing the filter from the user's language preference is no longer needed here. Thanks!