Next.js Supabase V3 (#463)

Version 3 of the kit:
- Radix UI replaced with Base UI (using the Shadcn UI patterns)
- next-intl replaces react-i18next
- enhanceAction deprecated; usage moved to next-safe-action
- main layout now wrapped with [locale] path segment
- Teams only mode
- Layout updates
- Zod v4
- Next.js 16.2
- Typescript 6
- All other dependencies updated
- Removed deprecated Edge CSRF
- Dynamic Github Action runner

packages/i18n/src/default-locale.ts

@@ -0,0 +1,7 @@
+/**
+ * @name defaultLocale
+ * @description The default locale of the application.
+ * @type {string}
+ * @default 'en'
+ */
+export const defaultLocale = process.env.NEXT_PUBLIC_DEFAULT_LOCALE ?? 'en';