feat(editor): add markdown presets, heading folding and external file refresh

frontend/src/stores/markdownPreferences.spec.ts

@@ -0,0 +1,20 @@
+// @vitest-environment happy-dom
+import { beforeEach, expect, it } from 'vitest'
+import { createPinia, setActivePinia } from 'pinia'
+import { nextTick } from 'vue'
+import { useMarkdownPreferencesStore, markdownPresets } from './markdownPreferences'
+beforeEach(() => { localStorage.clear(); setActivePinia(createPinia()) })
+it('saves, replaces and restores named syntax presets', async () => {
+  const store = useMarkdownPreferencesStore()
+  store.preferences.heading = 'setext'
+  store.preferences.bullet = '+'
+  expect(store.savePreset('我的格式')).toBe(true)
+  store.apply(markdownPresets.plain)
+  expect(store.normalized.callouts).toBe(false)
+  store.apply(store.customPresets[0]!.preferences)
+  expect(store.normalized.heading).toBe('setext')
+  await nextTick()
+  setActivePinia(createPinia())
+  expect(useMarkdownPreferencesStore().normalized.bullet).toBe('+')
+  expect(useMarkdownPreferencesStore().customPresets[0]!.name).toBe('我的格式')
+})