feat(desktop): expand and audit locale translations

[opencode-agent]

Summary

• add complete app, UI, and Desktop dictionaries for Azerbaijani, Finnish, Hindi, Indonesian, Italian, Dutch, Pakistani Punjabi (Shahmukhi), Swedish, Urdu, and Vietnamese
• enable the existing Turkish app/UI translation in Desktop and add its Desktop-specific dictionary
• source-review and correct all existing non-English app/UI/Desktop dictionaries using official language authorities plus established Microsoft, Apple, and Mozilla localization resources
• complete missing shared-app strings across existing locales
• register locale loading, native display labels, browser-language detection, and Traditional Chinese detection for Hong Kong, Taiwan, and Macao locale tags
• keep this translation-only: RTL layout, direction handling, and CSS are intentionally unchanged
• exclude Tamazight after source review showed the initial locale identity and translation could not meet the same confidence bar; IANA/CLDR distinguish zgh Standard Moroccan Tamazight from tzm Central Atlas Tamazight

Validation

• dictionary key and placeholder parity: app — 27 non-English locales × 995 keys
• dictionary key and placeholder parity: UI — 27 non-English locales × 171 keys
• dictionary key and placeholder parity: Desktop — 27 non-English locales × 21 keys
• independent per-key source-backed review for every added locale and every existing non-English locale
• git diff --check
• typecheck intentionally not run; CI will provide repository-level validation

Known localization constraint

The current catalogs expose only one and other for several counters. Arabic, Bosnian, Polish, Russian, and other languages need additional CLDR plural categories for perfect grammatical coverage. Reviewers used count-neutral wording where practical; changing the plural schema is intentionally outside this translation-only PR.

Requested by: @Hona (Luke Parker via Slack)