feat(files): show hidden new file name warning

Signed-off-by: skjnldsv <skjnldsv@protonmail.com>

apps/files/src/components/NewNodeDialog.vue

@@ -26,6 +26,11 @@
 				:helper-text="validity"
 				:label="label"
 				:value.sync="localDefaultName" />
+
+			<!-- Hidden file warning -->
+			<NcNoteCard v-if="isHiddenFileName"
+				type="warning"
+				:text="t('files', 'Files starting with a dot are hidden by default')" />
 		</form>
 	</NcDialog>
 </template>
@@ -35,12 +40,13 @@ import type { ComponentPublicInstance, PropType } from 'vue'
 import { getUniqueName } from '@nextcloud/files'
 import { t } from '@nextcloud/l10n'
 import { extname } from 'path'
-import { nextTick, onMounted, ref, watch, watchEffect } from 'vue'
+import { computed, nextTick, onMounted, ref, watch, watchEffect } from 'vue'
 import { getFilenameValidity } from '../utils/filenameValidity.ts'
 
 import NcButton from '@nextcloud/vue/components/NcButton'
 import NcDialog from '@nextcloud/vue/components/NcDialog'
 import NcTextField from '@nextcloud/vue/components/NcTextField'
+import NcNoteCard from '@nextcloud/vue/components/NcNoteCard'
 
 const props = defineProps({
 	/**
@@ -89,6 +95,11 @@ const nameInput = ref<ComponentPublicInstance>()
 const formElement = ref<HTMLFormElement>()
 const validity = ref('')
 
+const isHiddenFileName = computed(() => {
+	// Check if the name starts with a dot, which indicates a hidden file
+	return localDefaultName.value.trim().startsWith('.')
+})
+
 /**
  * Focus the filename input field
  */