feat(demo): 添加编辑模式切换功能并重构URL构建逻辑

添加复选框用于切换编辑模式，重构URL构建逻辑为独立函数
默认加载页面时为只读模式，保留当前文件路径切换模式时

demo.html

@@ -17,8 +17,12 @@
     <h3>父页面通过地址拼接加载子页面（filePath + mode=edit）</h3>
     <div class="panel">
       <input id="urlInput" type="text" placeholder="输入同源文件URL" />
+      <label style="display:flex;align-items:center;gap:6px;">
+        <input id="editModeToggle" type="checkbox" />
+        <span>编辑模式（勾选则拼接 mode=edit，不勾选为只读）</span>
+      </label>
       <button id="loadBtn">设置 iframe 地址</button>
-      <small>仅拼接 iframe src：vocd.html?filePath=URL&mode=edit</small>
+      <small>示例：vocd.html?filePath=URL&mode=edit 或 vocd.html?filePath=URL</small>
     </div>
     <iframe id="editorFrame" src="./vocd.html" referrerpolicy="no-referrer"></iframe>
 
@@ -26,23 +30,41 @@
       const editorFrame = document.getElementById('editorFrame')
       const loadBtn = document.getElementById('loadBtn')
       const urlInput = document.getElementById('urlInput')
+      const editModeToggle = document.getElementById('editModeToggle')
+
+      function buildSrc(filePath, isEdit) {
+        const base = './vocd.html'
+        return `${base}?filePath=${encodeURIComponent(filePath)}` + (isEdit ? '&mode=edit' : '')
+      }
 
       // 页面加载后，自动将 iframe 指向 vocd.html 并使用同源 /test.ocd
       document.addEventListener('DOMContentLoaded', () => {
         const defaultUrl = '/test.ocd' // 来自 public，同源可直接访问
         urlInput.value = defaultUrl
         const base = './vocd.html'
-        const src = `${base}?filePath=${encodeURIComponent(defaultUrl)}&mode=edit`
+        // 默认不勾选：只读模式（不拼接 mode）
+        editModeToggle.checked = false
+        const src = buildSrc(defaultUrl, editModeToggle.checked)
         editorFrame.src = src
         console.log('[demo] 自动设置 iframe src:', src)
       })
 
+      // 切换编辑模式时，刷新 iframe 地址，保留当前 filePath
+      editModeToggle.addEventListener('change', () => {
+        const typedUrl = urlInput.value.trim()
+        const currentAbs = editorFrame.src || './vocd.html'
+        const currentUrl = new URL(currentAbs, window.location.href)
+        const currentFilePath = currentUrl.searchParams.get('filePath') || (typedUrl || '/test.ocd')
+        const src = buildSrc(currentFilePath, editModeToggle.checked)
+        editorFrame.src = src
+        console.log('[demo] 编辑模式切换，刷新 iframe src:', src)
+      })
+
       loadBtn.onclick = () => {
         const typedUrl = urlInput.value.trim()
         const base = './vocd.html'
-        const src = typedUrl
-          ? `${base}?filePath=${encodeURIComponent(typedUrl)}&mode=edit`
-          : `${base}?mode=edit`
+        const targetUrl = typedUrl || '/test.ocd'
+        const src = buildSrc(targetUrl, editModeToggle.checked)
         editorFrame.src = src
         console.log('[demo] 设置 iframe src:', src)
       }