Implement authentication phase with Cidaas OAuth2 integration

- Add authentication middleware to protect routes
- Create API endpoints for login, logout, registration, and user info
- Develop UI components for login and registration forms
- Integrate VeeValidate for form validation
- Update environment configuration for Cidaas settings
- Add i18n support for English and German languages
- Enhance Tailwind CSS for improved styling of auth components
- Document authentication flow and testing procedures

app/components/ui/tabs/TabsTrigger.vue

@@ -0,0 +1,33 @@
+<script setup lang="ts">
+import type { TabsTriggerProps } from 'reka-ui'
+import type { HTMLAttributes } from 'vue'
+import { TabsTrigger, useForwardProps } from 'reka-ui'
+import { cn } from '~/lib/utils'
+
+interface Props extends TabsTriggerProps {
+  class?: HTMLAttributes['class']
+}
+
+const props = defineProps<Props>()
+
+const delegatedProps = computed(() => {
+  const { class: _, ...delegated } = props
+  return delegated
+})
+
+const forwarded = useForwardProps(delegatedProps)
+</script>
+
+<template>
+  <TabsTrigger
+    v-bind="forwarded"
+    :class="
+      cn(
+        'inline-flex items-center justify-center whitespace-nowrap rounded-lg px-4 py-2 text-base font-medium ring-offset-transparent transition-all focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-accent focus-visible:ring-offset-0 disabled:pointer-events-none disabled:opacity-50 text-white/70 hover:text-white data-[state=active]:bg-accent data-[state=active]:text-white data-[state=active]:shadow-md',
+        props.class
+      )
+    "
+  >
+    <slot />
+  </TabsTrigger>
+</template>