feat(mindspace): 公开页分享组件、workspace 路径与 Plaza 发布增强

- 新增 public share widget 与 workspace relative path 解析
- 增强 publications/chat-plaza 发布链路与缩略图 demo
- 补充 schema、cover 检查脚本与回归测试

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

plaza-public.mjs

@@ -152,29 +152,40 @@ export function renderPlazaPostRedirectHtml(post, targetUrl, { preview = false }
     (function () {
       var frame = document.querySelector('.post-frame');
       if (!frame) return;
+      var appliedHeight = 420;
       function applyHeight(height) {
-        frame.style.height = Math.max(Number(height) || 0, window.innerHeight, 420) + 'px';
+        var next = Math.max(Number(height) || 0, 420);
+        if (
+          appliedHeight > 420 &&
+          next > appliedHeight &&
+          frame.offsetHeight > 420 &&
+          next <= frame.offsetHeight + 24
+        ) {
+          return appliedHeight;
+        }
+        appliedHeight = Math.max(next, window.innerHeight, 420);
+        frame.style.height = appliedHeight + 'px';
+        return appliedHeight;
       }
       function measureFrameDocument() {
         try {
           var doc = frame.contentDocument;
           var body = doc && doc.body;
-          var root = doc && doc.documentElement;
-          if (!body && !root) return 0;
-          var measured = Math.max(
-            body ? body.scrollHeight : 0,
-            body ? body.offsetHeight : 0,
-            root ? root.scrollHeight : 0,
-            root ? root.offsetHeight : 0
-          );
-          if (body) {
-            for (var i = 0; i < body.children.length; i += 1) {
-              var child = body.children[i];
-              var rect = child.getBoundingClientRect();
-              measured = Math.max(measured, rect.bottom + (root ? root.scrollTop : 0));
-            }
+          if (!body) return 0;
+          var scrollTop = (doc.documentElement && doc.documentElement.scrollTop) || body.scrollTop || 0;
+          var measured = 0;
+          var blocks = body.querySelectorAll('.hero,.section,.quote-section,.footer,main,article');
+          for (var i = 0; i < blocks.length; i += 1) {
+            var el = blocks[i];
+            var rect = el.getBoundingClientRect();
+            measured = Math.max(measured, rect.bottom + scrollTop, el.offsetTop + el.offsetHeight);
           }
-          return Math.ceil(measured);
+          for (var j = 0; j < body.children.length; j += 1) {
+            var child = body.children[j];
+            var childRect = child.getBoundingClientRect();
+            measured = Math.max(measured, childRect.bottom + scrollTop, child.offsetTop + child.offsetHeight);
+          }
+          return Math.ceil(Math.max(measured, 420));
         } catch (error) {
           return 0;
         }