Add Ukrainian (ua) localization support 🇺🇦

[1h8sn0w]

What we need

Add Ukrainian language support to make the platform accessible to Ukrainian users.

What to do

• Add Ukrainian locale (ua) to supported languages
• Create Ukrainian translations in locales/ua.ts
• Add Ukrainian fields to database schema (titleUa, descriptionUa, slugUa)
• Update language selector with Ukrainian flag 🇺🇦
• Add Ukrainian currency (UAH) support
• Fix all TypeScript errors for missing Ukrainian fields

Technical stuff

• Follow the same pattern as other locales (en, es, pt, ru, zh-CN)
• Update all forms, components, and API endpoints
• Make sure Ukrainian content works everywhere

Why this matters

• Ukrainian users can use the platform in their language
• Better SEO for Ukrainian search terms
• Shows we care about international users

Reference

• Follow the same approach as Korean localization PR #120

---

Labels: enhancement, i18n