feat: Add database migrations and auth system

- Add Alembic for database migrations
- Implement user authentication system
- Update frontend styles and components
- Add new test audio functionality
- Update stream management and UI

static/footer.html

@@ -0,0 +1,12 @@
+<!-- Footer content -->
+<footer>
+  <p>Built for public voice streaming • Opus | Mono | 48 kHz | 60 kbps</p>
+  <p class="footer-hint">Need more space? Contact <a href="mailto:Andreas.Fleckl@dicta2stream.net">Andreas.Fleckl@dicta2stream.net</a></p>
+  <div class="footer-links">
+    <a href="#" data-target="terms-page">Terms</a>
+    <span class="separator">•</span>
+    <a href="#" data-target="privacy-page">Privacy</a>
+    <span class="separator">•</span>
+    <a href="#" data-target="imprint-page">Imprint</a>
+  </div>
+</footer>