fix(mindspace): 修复删除时无法解析 MySQL JSON 导致页面复活

source_snapshot_json 在 mysql2 中已是对象，JSON.parse 失败会使 relative_path 丢失、工作区 HTML 未清理；同步后页面重新出现。

Co-authored-by: Cursor <cursoragent@cursor.com>

mindspace-page-sync.mjs

@@ -52,6 +52,16 @@ async function findPageByWorkspaceRelativePath(pool, userId, relativePath) {
   return { id: row.id, updatedAt: Number(row.updated_at ?? 0) };
 }
 
+function parseJsonColumn(value, fallback = {}) {
+  if (value == null || value === '') return { ...fallback };
+  if (typeof value === 'object' && !Buffer.isBuffer(value)) return value;
+  try {
+    return JSON.parse(String(value));
+  } catch {
+    return { ...fallback };
+  }
+}
+
 async function loadIndexedWorkspacePages(pool, userId) {
   const [rows] = await pool.query(
     `SELECT p.id, p.updated_at, p.source_asset_id, pv.source_snapshot_json
@@ -62,12 +72,7 @@ async function loadIndexedWorkspacePages(pool, userId) {
   );
   const byPath = new Map();
   for (const row of rows) {
-    let snapshot = {};
-    try {
-      snapshot = JSON.parse(row.source_snapshot_json ?? '{}');
-    } catch {
-      snapshot = {};
-    }
+    const snapshot = parseJsonColumn(row.source_snapshot_json);
     const relativePath = normalizePublicHtmlPath(snapshot.relative_path);
     if (relativePath) {
       byPath.set(relativePath, {