feat: Add Russian and Ukrainian (#3692)

This PR adds Russian and Ukrainian locales for II.

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: aterga

src/frontend/src/lib/constants/locale.constants.ts

@@ -8,6 +8,8 @@ export const availableLocales = [
   "id",
   "it",
   "pl",
+  "ru",
+  "uk",
   "ur",
 ];
 
@@ -21,6 +23,8 @@ export const enabledLocales = [
   "id",
   "it",
   "pl",
+  "ru",
+  "uk",
   "ur",
 ];