feat: keep show showPreview (#111)

Co-authored-by: anatawa12 <anatawa12@icloud.com>

packages/frontend/src/components/MkPostForm.vue

@@ -166,7 +166,8 @@ let poll = $ref<{
 	expiredAfter: string | null;
 } | null>(null);
 let useCw = $ref(false);
-let showPreview = $ref(false);
+let showPreview = $ref(defaultStore.state.showPreview);
+watch($$(showPreview), () => defaultStore.set('showPreview', showPreview));
 let cw = $ref<string | null>(null);
 let localOnly = $ref<boolean>(props.initialLocalOnly ?? defaultStore.state.rememberNoteVisibility ? defaultStore.state.localOnly : defaultStore.state.defaultNoteLocalOnly);
 let visibility = $ref(props.initialVisibility ?? (defaultStore.state.rememberNoteVisibility ? defaultStore.state.visibility : defaultStore.state.defaultNoteVisibility) as typeof misskey.noteVisibilities[number]);

packages/frontend/src/store.ts

@@ -130,6 +130,10 @@ export const defaultStore = markRaw(new Storage('base', {
 		where: 'deviceAccount',
 		default: false,
 	},
+	showPreview: {
+		where: 'deviceAccount',
+		default: false,
+	},
 	statusbars: {
 		where: 'deviceAccount',
 		default: [] as {