feat: add Spanish language support

Added complete Spanish (es) translation for the Biblical Guide application:
- Created messages/es.json with full Spanish translations
- Updated i18n.ts to include Spanish locale
- Updated middleware.ts to handle Spanish routes
- Added Spanish to language options in all locale files

Users can now access the app in Spanish at /es/* routes and select Spanish from the language settings.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

middleware.ts

@@ -62,7 +62,7 @@ export async function middleware(request: NextRequest) {
     if (!token) {
       // Extract locale from pathname for redirect
       const locale = request.nextUrl.pathname.split('/')[1]
-      const isValidLocale = ['ro', 'en'].includes(locale)
+      const isValidLocale = ['ro', 'en', 'es'].includes(locale)
       const redirectLocale = isValidLocale ? locale : 'en'
 
       return NextResponse.redirect(new URL(`/${redirectLocale}/auth/login`, request.url))
@@ -83,6 +83,6 @@ export const config = {
     // - favicon.ico, robots.txt, sitemap.xml
     '/((?!api|admin|_next|_vercel|.*\\..*|favicon.ico|robots.txt|sitemap.xml).*)',
     // Match internationalized pathnames
-    '/(ro|en)/:path*'
+    '/(ro|en|es)/:path*'
   ],
 }