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

frontend/src/stores/headingAppearance.ts

@@ -0,0 +1,40 @@
+import { defineStore } from 'pinia'
+import { computed, ref, watch } from 'vue'
+import '@/styles/headings.css'
+
+const key = 'editor-heading-appearance'
+export const defaultHeadingSizes = [32, 28, 24, 21, 18, 16]
+export function normalizeHeadingAppearance(value: unknown) {
+  const raw = value && typeof value === 'object' ? value as Record<string, unknown> : {}
+  const levels = Array.isArray(raw.levels) ? raw.levels : []
+  return {
+    custom: raw.custom === true,
+    family: ['inherit', 'serif', 'sans-serif', 'monospace'].includes(String(raw.family)) ? String(raw.family) : 'inherit',
+    levels: defaultHeadingSizes.map((size, index) => {
+      const item = levels[index] ?? {}
+      return {
+        size: typeof item.size === 'number' && Number.isFinite(item.size) ? Math.min(72, Math.max(12, item.size)) : size,
+        weight: [400, 500, 600, 700, 800].includes(item.weight) ? Number(item.weight) : 700,
+      }
+    }),
+  }
+}
+
+export const useHeadingAppearanceStore = defineStore('heading-appearance', () => {
+  let saved: unknown
+  try { saved = JSON.parse(localStorage.getItem(key) ?? '{}') } catch { saved = {} }
+  const preferences = ref(normalizeHeadingAppearance(saved))
+  watch(preferences, value => localStorage.setItem(key, JSON.stringify(normalizeHeadingAppearance(value))), { deep: true })
+  const cssVariables = computed(() => {
+    const normalized = normalizeHeadingAppearance(preferences.value)
+    if (!normalized.custom) return {}
+    const result: Record<string, string> = { '--heading-family': normalized.family }
+    normalized.levels.forEach((item, index) => {
+      result[`--heading-${index + 1}-size`] = `${item.size}px`
+      result[`--heading-${index + 1}-weight`] = String(item.weight)
+    })
+    return result
+  })
+  function reset() { preferences.value = normalizeHeadingAppearance({}) }
+  return { preferences, cssVariables, reset }
+})