fix: remove remaining uses of isSuperuser flag

The dashboard should generally only check for permissions not flags.

src/components/shows/AddShowButton.vue

 <template>
-  <template v-if="authStore.isSuperuser">
-    <AddShowModal ref="addShowModal" v-bind="attrs" />
+  <AddShowModal ref="addShowModal" v-bind="attrs" />
 
-    <button
-      type="button"
-      :data-testid="testId"
-      class="btn btn-default md:tw-whitespace-nowrap"
-      @click="addShowModal.open()"
-    >
-      {{ t('showCreator.title') }}
-    </button>
-  </template>
+  <button
+    type="button"
+    :data-testid="testId"
+    class="btn btn-default md:tw-whitespace-nowrap"
+    @click="addShowModal.open()"
+  >
+    {{ t('showCreator.title') }}
+  </button>
 </template>
 
 <script lang="ts" setup>
@@ -18,7 +16,6 @@ import { ref, useAttrs } from 'vue'
 
 import AddShowModal from './AddShowModal.vue'
 import { useI18n } from '@/i18n'
-import { useAuthStore } from '@/stores/auth'
 
 defineOptions({
   inheritAttrs: false,
@@ -29,7 +26,6 @@ defineProps<{
 }>()
 
 const attrs = useAttrs()
-const authStore = useAuthStore()
 const { t } = useI18n()
 
 const addShowModal = ref()

src/stores/auth.ts

@@ -121,7 +121,6 @@ export const useAuthStore = defineStore('auth', () => {
   const currentUser = ref<CurrentUser>()
   const _steeringUser = ref<SteeringUser>()
   const steeringUser = computed(() => (currentUser.value ? _steeringUser.value : undefined))
-  const isSuperuser = computed(() => steeringUser.value?.isSuperuser === true)
   const sessionInitializationState = ref<SessionInitializationState>()
   const isInitializingSession = computed(() => sessionInitializationState.value !== undefined)
 
@@ -202,7 +201,6 @@ export const useAuthStore = defineStore('auth', () => {
   return {
     currentUser: shallowReadonly(currentUser),
     steeringUser,
-    isSuperuser,
     sessionInitializationState: readonly(sessionInitializationState),
     isInitializingSession: readonly(isInitializingSession),
     init,