公开页补齐自引用 Canonical 与按类型的结构化数据，图片补上说明文字。

后台设置和内容编辑改成可导航布局；部署用访客 origin 生成 Canonical，避免落到容器地址。

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

frontend/components/admin/AdminField.tsx

@@ -15,6 +15,9 @@ export default function AdminField({
   disabled,
   className = "",
   minHeight,
+  embed,
+  error,
+  describedBy,
 }: {
   id: string;
   label: ReactNode;
@@ -29,27 +32,40 @@ export default function AdminField({
   disabled?: boolean;
   className?: string;
   minHeight?: string;
+  /** 标签由外层设置行提供，本组件只保留计数与输入 */
+  embed?: boolean;
+  error?: string;
+  describedBy?: string;
 }) {
   const handle = (e: ChangeEvent<HTMLInputElement | HTMLTextAreaElement>) =>
     onChange(e.target.value);
 
+  const invalid = Boolean(error);
+  const described = [describedBy, error ? `${id}-error` : null].filter(Boolean).join(" ") || undefined;
+
+  const count =
+    maxLength != null ? (
+      <span className={`admin-field-count${embed ? " is-infield" : ""}`} aria-hidden>
+        {value.length}/{maxLength}
+      </span>
+    ) : null;
+
   return (
     <div className={className}>
-      <div className="admin-field-head">
-        <label className="field-label" htmlFor={id}>
-          {label}
-        </label>
-        {maxLength != null && (
-          <span className="admin-field-count" aria-hidden>
-            {value.length}/{maxLength}
-          </span>
-        )}
-      </div>
-      {hint != null && hint !== "" && (
+      {embed ? null : (
+        <div className="admin-field-head">
+          <label className="field-label" htmlFor={id}>
+            {label}
+          </label>
+          {count}
+        </div>
+      )}
+      {!embed && hint != null && hint !== "" && (
         <p className="meta text-[12.5px] mb-2.5 leading-relaxed">{hint}</p>
       )}
       {as === "textarea" ? (
-        <div className="admin-field-shell is-area">
+        <div className={`admin-field-shell is-area${embed && count ? " has-count" : ""}${invalid ? " is-invalid" : ""}`}>
+          {embed ? count : null}
           <textarea
             id={id}
             className="admin-field-input"
@@ -59,10 +75,12 @@ export default function AdminField({
             onChange={handle}
             placeholder={placeholder}
             disabled={disabled}
+            aria-invalid={invalid || undefined}
+            aria-describedby={described}
           />
         </div>
       ) : (
-        <div className="admin-field-shell">
+        <div className={`admin-field-shell${embed && count ? " has-count" : ""}${invalid ? " is-invalid" : ""}`}>
           <input
             id={id}
             type={type}
@@ -73,9 +91,17 @@ export default function AdminField({
             placeholder={placeholder}
             autoComplete={autoComplete}
             disabled={disabled}
+            aria-invalid={invalid || undefined}
+            aria-describedby={described}
           />
+          {embed ? count : null}
         </div>
       )}
+      {error ? (
+        <p className="admin-settings-row-error" id={`${id}-error`} role="alert">
+          {error}
+        </p>
+      ) : null}
     </div>
   );
 }