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/form/FormMessage.vue

@@ -0,0 +1,44 @@
+<script setup lang="ts">
+import type { HTMLAttributes } from 'vue'
+import { inject } from 'vue'
+import { useFieldError } from 'vee-validate'
+import { cn } from '~/lib/utils'
+import type { FormItemContext } from '.'
+import { FORM_ITEM_INJECT_KEY } from '.'
+
+/**
+ * FormMessage component - Displays validation error messages
+ * Only renders when there is an error for the associated field
+ */
+
+interface Props {
+  class?: HTMLAttributes['class']
+}
+
+const props = defineProps<Props>()
+
+// Get the form item context for ID
+const formItemContext = inject<FormItemContext>(FORM_ITEM_INJECT_KEY)
+
+// Get the field error message from the nearest parent field
+const error = useFieldError()
+</script>
+
+<template>
+  <Transition
+    enter-active-class="transition-all duration-200 ease-out"
+    enter-from-class="opacity-0 -translate-y-1"
+    enter-to-class="opacity-100 translate-y-0"
+    leave-active-class="transition-all duration-150 ease-in"
+    leave-from-class="opacity-100 translate-y-0"
+    leave-to-class="opacity-0 -translate-y-1"
+  >
+    <p
+      v-if="error"
+      :id="`${formItemContext?.id}-message`"
+      :class="cn('form-error', props.class)"
+    >
+      {{ error }}
+    </p>
+  </Transition>
+</template>