Fix AI streaming, learn images, and full city regions.

Remove use server from stream helper to fix RSC errors; support OPENAI_API_BASE alias; render HTML tables via rehype-raw with gua-image API; expand regions to 356 prefecture-level cities.

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

components/learn/markdown-content.tsx

@@ -1,6 +1,8 @@
 import Link from "next/link";
 import Markdown from "react-markdown";
+import rehypeRaw from "rehype-raw";
 import type { LearnVariant } from "@/lib/content/gua-utils";
+import { guaNumFromMark } from "@/lib/content/gua-utils";
 
 function resolveLearnHref(
   href: string | undefined,
@@ -31,19 +33,48 @@ function resolveLearnHref(
     const num = mark.split(".")[0];
     return `${base}/${num}`;
   }
+  if (/^\.\.\/\d{2}\./.test(href)) {
+    const num = href.replace(/^\.\.\//, "").split(".")[0];
+    return `${base}/${num}`;
+  }
+  if (/^\d{2}\./.test(href)) {
+    const num = href.split(".")[0];
+    return `${base}/${num}`;
+  }
   return href;
 }
 
+function resolveImageSrc(
+  src: string | undefined,
+  variant: LearnVariant,
+  guaNum: string,
+): string | undefined {
+  if (!src) {
+    return src;
+  }
+  if (src.startsWith("http://") || src.startsWith("https://")) {
+    return src;
+  }
+  const file = src.replace(/^\.\//, "").split("/").pop() ?? src;
+  const apiVariant = variant === "traditional" ? "traditional" : "simplified";
+  return `/api/gua-image/${apiVariant}/${guaNum}/${encodeURIComponent(file)}`;
+}
+
 export default function MarkdownContent({
   content,
   variant = "traditional",
+  guaMark,
 }: {
   content: string;
   variant?: LearnVariant;
+  guaMark: string;
 }) {
+  const guaNum = guaNumFromMark(guaMark);
+
   return (
     <Markdown
-      className="prose max-w-none dark:prose-invert prose-headings:scroll-mt-20 prose-a:text-primary"
+      className="prose max-w-none dark:prose-invert prose-headings:scroll-mt-20 prose-a:text-primary prose-table:text-sm"
+      rehypePlugins={[rehypeRaw]}
       components={{
         a: ({ href, children, ...props }) => {
           const resolved = resolveLearnHref(href, variant);
@@ -60,15 +91,24 @@ export default function MarkdownContent({
             </a>
           );
         },
-        img: ({ src, alt, ...props }) => {
-          if (typeof src === "string" && !src.startsWith("http")) {
-            return (
-              <span className="my-2 block rounded border border-dashed p-4 text-center text-sm text-muted-foreground">
-                [{alt || "卦象图片"}]
-              </span>
-            );
+        img: ({ src, alt }) => {
+          const resolved = resolveImageSrc(
+            typeof src === "string" ? src : undefined,
+            variant,
+            guaNum,
+          );
+          if (!resolved) {
+            return null;
           }
-          return <img src={src} alt={alt} {...props} />;
+          return (
+            // eslint-disable-next-line @next/next/no-img-element
+            <img
+              src={resolved}
+              alt={alt ?? "卦象图片"}
+              className="mx-auto h-auto max-w-[120px]"
+              loading="lazy"
+            />
+          );
         },
       }}
     >