fix: 管理删评对公众剥离作者身份，评论者本人仍可见原文

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

frontend/app/globals.css

@@ -3913,7 +3913,7 @@ html.dark .prose-content pre[data-theme] span {
   font-size: 13.5px;
 }
 
-/* 软删占位：头像/昵称马赛克，可读结构但不可辨认身份 */
+/* 软删占位：匿名马赛克（不含真实头像/昵称） */
 .cmt-mosaic-avatar {
   position: relative;
   display: inline-flex;
@@ -3923,9 +3923,11 @@ html.dark .prose-content pre[data-theme] span {
   user-select: none;
   flex-shrink: 0;
 }
-.cmt-mosaic-avatar > * {
-  filter: blur(7px) saturate(0.35) contrast(0.9);
-  transform: scale(1.2);
+.cmt-mosaic-avatar-fill {
+  display: block;
+  width: 100%;
+  height: 100%;
+  background: color-mix(in srgb, var(--ink-3) 50%, var(--panel));
 }
 .cmt-mosaic-avatar::after {
   content: "";
@@ -3947,15 +3949,34 @@ html.dark .prose-content pre[data-theme] span {
   pointer-events: none;
 }
 .cmt-mosaic-name {
+  position: relative;
   display: inline-block;
-  max-width: 9rem;
+  width: 4.5rem;
+  height: 14px;
+  border-radius: 4px;
   overflow: hidden;
-  white-space: nowrap;
-  filter: blur(5px);
-  letter-spacing: 0.04em;
-  user-select: none;
+  background: color-mix(in srgb, var(--ink-3) 40%, var(--panel));
+  pointer-events: none;
+  user-select: none;
+  vertical-align: middle;
+}
+.cmt-mosaic-name::after {
+  content: "";
+  position: absolute;
+  inset: 0;
+  background-image:
+    repeating-linear-gradient(
+      0deg,
+      color-mix(in srgb, var(--ink) 18%, transparent) 0 1px,
+      transparent 1px 3px
+    ),
+    repeating-linear-gradient(
+      90deg,
+      color-mix(in srgb, var(--ink) 18%, transparent) 0 1px,
+      transparent 1px 3px
+    );
+  mix-blend-mode: soft-light;
   pointer-events: none;
-  transform: scaleY(1.05);
 }
 .cmt-tombstone {
   border-radius: 12px;

frontend/app/post/[id]/page.tsx

@@ -546,10 +546,12 @@ export default async function PostDetailPage({ params, searchParams }: PageProps
           "@type": "Comment",
           text: acceptedAnswer.content,
           dateCreated: acceptedAnswer.created_at,
-          author: {
-            "@type": "Person",
-            name: acceptedAnswer.user.nickname || acceptedAnswer.user.username,
-          },
+          author: acceptedAnswer.user
+            ? {
+                "@type": "Person",
+                name: acceptedAnswer.user.nickname || acceptedAnswer.user.username,
+              }
+            : undefined,
           url: `#comment-${acceptedAnswer.id}`,
         },
       }),