feat(lightbox): 用户主页头像可预览，图箱支持缩放旋转反色

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

frontend/app/globals.css

@@ -4579,28 +4579,57 @@ html.dark .prose-content pre[data-theme] span {
   inset: 0;
   z-index: 1200;
   display: flex;
-  align-items: center;
-  justify-content: center;
-  padding: 1.5rem;
+  flex-direction: column;
   background: rgba(0, 0, 0, 0.82);
   backdrop-filter: blur(2px);
 }
+.md-lightbox-stage {
+  flex: 1;
+  min-height: 0;
+  width: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  overflow: hidden;
+  touch-action: none;
+}
+.md-lightbox-stage.is-zoomed { cursor: grab; }
+.md-lightbox-stage.is-panning { cursor: grabbing; }
 .md-lightbox-figure {
   margin: 0;
-  max-width: min(96vw, 1200px);
-  max-height: 90vh;
   display: flex;
-  flex-direction: column;
   align-items: center;
-  gap: 0.75rem;
+  justify-content: center;
 }
 .md-lightbox-img {
-  max-width: 100%;
-  max-height: calc(90vh - 3rem);
+  max-width: min(92vw, 1200px);
+  max-height: calc(100vh - 8.5rem);
   object-fit: contain;
   border-radius: 8px;
   box-shadow: 0 12px 40px rgba(0, 0, 0, 0.45);
   user-select: none;
+  transform-origin: center center;
+  transition: transform 0.15s ease, filter 0.15s ease;
+}
+.md-lightbox-img.is-odd-rot {
+  max-width: calc(100vh - 8.5rem);
+  max-height: min(92vw, 1200px);
+}
+.md-lightbox-stage.is-panning .md-lightbox-img,
+.md-lightbox-img.is-snap {
+  transition: none;
+}
+.md-lightbox-footer {
+  position: absolute;
+  bottom: 1rem;
+  left: 50%;
+  transform: translateX(-50%);
+  z-index: 2;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 0.5rem;
+  max-width: calc(100vw - 2rem);
 }
 .md-lightbox-caption {
   color: rgba(255, 255, 255, 0.85);
@@ -4608,10 +4637,74 @@ html.dark .prose-content pre[data-theme] span {
   text-align: center;
   max-width: 40rem;
   line-height: 1.5;
+  margin: 0;
+  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.55);
+}
+.md-lightbox-toolbar {
+  display: flex;
+  align-items: center;
+  gap: 2px;
+  padding: 5px;
+  border-radius: 999px;
+  background: rgba(0, 0, 0, 0.48);
+  backdrop-filter: blur(10px);
+  max-width: 100%;
+  overflow-x: auto;
+}
+.md-lightbox-tool,
+.md-lightbox-zoom-label {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  border: none;
+  border-radius: 999px;
+  background: transparent;
+  color: #fff;
+  cursor: pointer;
+  transition: background 0.15s ease;
+}
+.md-lightbox-tool {
+  width: 36px;
+  height: 36px;
+  flex-shrink: 0;
+}
+.md-lightbox-zoom-label {
+  min-width: 3.25rem;
+  height: 36px;
+  padding: 0 0.35rem;
+  font-size: 12px;
+  font-variant-numeric: tabular-nums;
+  letter-spacing: 0.02em;
+}
+.md-lightbox-tool:hover,
+.md-lightbox-zoom-label:hover {
+  background: rgba(255, 255, 255, 0.14);
+}
+.md-lightbox-tool.is-on {
+  background: rgba(255, 255, 255, 0.22);
+}
+.md-lightbox-tool:disabled,
+.md-lightbox-zoom-label:disabled {
+  opacity: 0.35;
+  cursor: default;
+  background: transparent;
+}
+.md-lightbox-tool:focus-visible,
+.md-lightbox-zoom-label:focus-visible {
+  outline: 2px solid rgba(255, 255, 255, 0.7);
+  outline-offset: 1px;
+}
+.md-lightbox-sep {
+  width: 1px;
+  height: 16px;
+  margin: 0 4px;
+  background: rgba(255, 255, 255, 0.22);
+  flex-shrink: 0;
 }
 .md-lightbox-close,
 .md-lightbox-nav {
   position: absolute;
+  z-index: 3;
   display: inline-flex;
   align-items: center;
   justify-content: center;
@@ -4641,14 +4734,12 @@ html.dark .prose-content pre[data-theme] span {
 .md-lightbox-prev { left: 1rem; }
 .md-lightbox-next { right: 1rem; }
 .md-lightbox-counter {
-  position: absolute;
-  bottom: 1.25rem;
-  left: 50%;
-  transform: translateX(-50%);
   color: rgba(255, 255, 255, 0.8);
-  font-size: 13px;
+  font-size: 12.5px;
   font-variant-numeric: tabular-nums;
   letter-spacing: 0.04em;
+  padding: 0 0.55rem;
+  white-space: nowrap;
 }
 
 /* 评论区的 Markdown 紧凑排版：继承 prose-content 全部规则，仅收紧行距与间距 */

frontend/app/u/[id]/ProfileHeroAvatar.tsx

@@ -0,0 +1,58 @@
+"use client";
+
+import { useState } from "react";
+import Avatar from "@/components/Avatar";
+import ImageLightbox from "@/components/markdown/ImageLightbox";
+
+const RING_STYLE = {
+  width: 80,
+  height: 80,
+  lineHeight: 0,
+  boxShadow:
+    "0 0 0 4px var(--panel), 0 0 0 6px color-mix(in srgb, var(--accent) 38%, transparent)",
+} as const;
+
+const RING_CLASS =
+  "inline-flex items-center justify-center shrink-0 rounded-full p-0";
+
+/** 用户主页 Hero 头像：有实图时可点击，复用正文图箱预览 */
+export default function ProfileHeroAvatar({
+  name,
+  src,
+}: {
+  name: string;
+  src?: string;
+}) {
+  const [open, setOpen] = useState(false);
+  const canPreview = !!src;
+  const alt = `${name} 的头像`;
+
+  return (
+    <>
+      {canPreview ? (
+        <button
+          type="button"
+          className={`${RING_CLASS} border-0 bg-transparent cursor-zoom-in outline-none focus-visible:ring-2 focus-visible:ring-[var(--accent)] focus-visible:ring-offset-2 focus-visible:ring-offset-[var(--panel)]`}
+          style={RING_STYLE}
+          aria-label="查看头像"
+          data-tip="查看头像"
+          onClick={() => setOpen(true)}
+        >
+          <Avatar name={name} src={src} size={80} />
+        </button>
+      ) : (
+        <span className={RING_CLASS} style={RING_STYLE}>
+          <Avatar name={name} src={src} size={80} />
+        </span>
+      )}
+      {open && src ? (
+        <ImageLightbox
+          items={[{ src, alt }]}
+          index={0}
+          onClose={() => setOpen(false)}
+          onIndexChange={() => {}}
+        />
+      ) : null}
+    </>
+  );
+}

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

@@ -11,7 +11,7 @@ import { getMeCached, getPublicSettingsCached } from "@/lib/serverData";
 import UserProfileContent from "./UserProfileContent";
 import ProfileForm from "./ProfileForm";
 import PasswordForm from "./PasswordForm";
-import Avatar from "@/components/Avatar";
+import ProfileHeroAvatar from "./ProfileHeroAvatar";
 import RoleBadge from "@/components/RoleBadge";
 import { roleMeta } from "@/lib/roles";
 import StartDMButton from "./StartDMButton";
@@ -181,22 +181,10 @@ export default async function UserPage({ params, searchParams }: UserPageProps)
         {/* 身份信息：纯文档流，头像 + 右侧文字 baseline 对齐 */}
         <div className="relative z-10 px-5 sm:px-7 pt-5 sm:pt-6">
           <div className="flex items-center gap-4">
-            <span
-              className="inline-flex items-center justify-center shrink-0 rounded-full p-0"
-              style={{
-                width: 80,
-                height: 80,
-                lineHeight: 0,
-                boxShadow:
-                  "0 0 0 4px var(--panel), 0 0 0 6px color-mix(in srgb, var(--accent) 38%, transparent)",
-              }}
-            >
-              <Avatar
-                name={u.nickname || u.username}
-                src={u.avatar || undefined}
-                size={80}
-              />
-            </span>
+            <ProfileHeroAvatar
+              name={u.nickname || u.username}
+              src={u.avatar || undefined}
+            />
             <div className="flex-1 min-w-0">
               <div className="flex items-center gap-2 flex-wrap">
                 <h1