feat(ui): add alignment props on alert component

front/src/components/ui/Alert.vue

@@ -1,7 +1,8 @@
 <script setup lang="ts">
 import { type PastelProps, color } from '~/composables/color'
+import { type AlignmentProps, align } from '~/composables/alignment'
 
-export type Props = PastelProps
+export type Props = PastelProps & AlignmentProps
 
 const props = defineProps<Props>()
 </script>
@@ -9,7 +10,8 @@ const props = defineProps<Props>()
 <template>
   <div
     class="funkwhale is-colored solid alert"
-    v-bind="color(props)()"
+    role="alert"
+    v-bind="color(align(props)())"
   >
     <slot />