✨ feat(etl): Add ETL authentication and navigation

Add Keycloak authentication for ETL users.
Configure ETL routes and login/logout functionality.
Integrate ETL with Keycloak SSO.
Update vite.config.js to include etl.js.
Create EtlController with home, login, and logout routes.
Implement EtlAuthenticator for email/password login.
Configure security.yaml for ETL firewall and providers.
Add etl.js and etl.scss for ETL frontend.
Add Keycloak client configuration for ETL.
Update PrestaireController to use absolute URL for login.

assets/etl.js

@@ -0,0 +1,3 @@
+import './etl.scss';
+
+console.log('ETL Mobile Loaded');

assets/etl.scss

@@ -0,0 +1,10 @@
+@import "tailwindcss";
+
+body {
+    @apply bg-slate-50 text-slate-900 font-sans antialiased;
+    -webkit-tap-highlight-color: transparent;
+}
+
+.mobile-container {
+    @apply max-w-md mx-auto min-h-screen flex flex-col relative bg-white shadow-2xl overflow-hidden;
+}