chore: add techbase to apps-archived

Integrated techbase (software comparison platform) into monorepo structure:
- Created NestJS backend with votes and comments modules
- Migrated from external Supabase to own PostgreSQL
- Set up Drizzle ORM schema for votes and comments
- Created API client replacing Supabase in Astro frontend
- Added environment configuration (port 3021)

Archived immediately as it's not yet ready for active development.

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

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

apps-archived/techbase/apps/web/src/components/LanguageSwitcher.astro

@@ -0,0 +1,52 @@
+---
+import { getLocaleFromUrl, getLocalizedUrl } from '../utils/i18n';
+
+const locale = getLocaleFromUrl(Astro.url);
+const pathname = Astro.url.pathname;
+const currentPath = pathname.replace(new RegExp(`^/${locale}`), '') || '/';
+
+const languages = [
+  { code: 'de', name: 'Deutsch' },
+  { code: 'en', name: 'English' }
+];
+---
+
+<div class="relative" x-data="{ open: false }">
+  <button 
+    @click="open = !open" 
+    class="flex items-center space-x-1 p-2 rounded hover:bg-gray-100 dark:hover:bg-gray-700 text-gray-700 dark:text-gray-300 transition-colors duration-200"
+  >
+    <span>{locale === 'de' ? 'DE' : 'EN'}</span>
+    <svg xmlns="http://www.w3.org/2000/svg" class="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+      <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7" />
+    </svg>
+  </button>
+  
+  <div 
+    x-show="open" 
+    @click.away="open = false" 
+    class="absolute right-0 mt-2 w-48 bg-white dark:bg-gray-800 shadow-lg rounded-md overflow-hidden z-10 border border-gray-200 dark:border-gray-700 transition-colors duration-200"
+    x-transition:enter="transition ease-out duration-100"
+    x-transition:enter-start="transform opacity-0 scale-95"
+    x-transition:enter-end="transform opacity-100 scale-100"
+    x-transition:leave="transition ease-in duration-75"
+    x-transition:leave-start="transform opacity-100 scale-100"
+    x-transition:leave-end="transform opacity-0 scale-95"
+    style="display: none;"
+  >
+    <div class="py-1">
+      {languages.map(lang => (
+        <a 
+          href={getLocalizedUrl(currentPath, lang.code)}
+          class={`block px-4 py-2 text-sm transition-colors duration-200 ${
+            locale === lang.code 
+              ? 'bg-gray-100 dark:bg-gray-700 text-primary dark:text-blue-400' 
+              : 'text-gray-700 dark:text-gray-300 hover:bg-gray-50 dark:hover:bg-gray-700'
+          }`}
+        >
+          {lang.name}
+        </a>
+      ))}
+    </div>
+  </div>
+</div>