fix(single): author card follow and identity parity

Add follow CTA to after-box author card, wrap bar label in span, and
harden follow.js label updates when span is missing.

assets/js/follow.js

@@ -68,16 +68,28 @@
   function updateFollowButton(btn, isFollowing, count) {
     var icon = btn.querySelector('i');
     var text = btn.querySelector('span');
+    function setLabel(label) {
+      if (text) {
+        text.textContent = label;
+        return;
+      }
+      // Fallback when markup has bare text nodes next to the icon.
+      var nodes = Array.prototype.slice.call(btn.childNodes);
+      var textNode = nodes.filter(function (n) { return n.nodeType === 3 && n.textContent.trim() !== ''; })[0];
+      if (textNode) {
+        textNode.textContent = ' ' + label + ' ';
+      }
+    }
 
     if (isFollowing) {
       btn.classList.add('is-following');
       if (icon) icon.className = 'fas fa-heart';
-      if (text) text.textContent = '已关注';
+      setLabel('已关注');
       btn.title = '点击取消关注';
     } else {
       btn.classList.remove('is-following');
       if (icon) icon.className = 'far fa-heart';
-      if (text) text.textContent = '关注';
+      setLabel('关注');
       btn.title = '关注该用户';
     }