Initial commit: OAuth IAM Laravel application

Laravel-based OAuth/IAM service with Passport, Vue 3 frontend, and
Docker Compose setup for local and production deployment.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

resources/js/composables/useTheme.ts

@@ -0,0 +1,16 @@
+import { ref } from 'vue';
+
+// El estado inicial ya lo aplicó el script inline en app.blade.php (evita el
+// flash); acá solo reflejamos esa clase para que el ícono del toggle arranque
+// sincronizado.
+const isDark = ref(document.documentElement.classList.contains('dark'));
+
+function toggleTheme(): void {
+    isDark.value = !isDark.value;
+    document.documentElement.classList.toggle('dark', isDark.value);
+    localStorage.setItem('theme', isDark.value ? 'dark' : 'light');
+}
+
+export function useTheme() {
+    return { isDark, toggleTheme };
+}