feat: 完善会话交互并统一聊天页视觉样式

补齐会话重命名/删除与会话菜单能力，新增聊天参数透传与本地开关持久化，并统一输入区、消息区、代码块和弹框等关键交互样式。

Made-with: Cursor

src/components/StreamMessage.tsx

@@ -1,3 +1,6 @@
+import { useState } from "react";
+import { CheckOutlined, CopyOutlined } from "@ant-design/icons";
+import { Button, message } from "antd";
 import ReactMarkdown from "react-markdown";
 import remarkGfm from "remark-gfm";
 import remarkMath from "remark-math";
@@ -5,19 +8,68 @@ import rehypeKatex from "rehype-katex";
 import rehypeHighlight from "rehype-highlight";
 import "katex/dist/katex.min.css";
 import "highlight.js/styles/github.css";
+import type { ReactNode } from "react";
 
 type StreamMessageProps = {
   content: string;
 };
 
+function extractText(node: ReactNode): string {
+  if (typeof node === "string") return node;
+  if (typeof node === "number") return String(node);
+  if (!node) return "";
+  if (Array.isArray(node)) return node.map((item) => extractText(item)).join("");
+  if (typeof node === "object" && "props" in node) {
+    const child = (node as { props?: { children?: ReactNode } }).props?.children;
+    return extractText(child);
+  }
+  return "";
+}
+
+function MarkdownPreBlock(props: { children: ReactNode }) {
+  const [copied, setCopied] = useState(false);
+  const codeText = extractText(props.children).replace(/\n$/, "");
+
+  const onCopy = async () => {
+    try {
+      await navigator.clipboard.writeText(codeText);
+      setCopied(true);
+      message.success("代码已复制");
+      window.setTimeout(() => setCopied(false), 1200);
+    } catch {
+      message.error("复制失败");
+    }
+  };
+
+  return (
+    <div className="my-2 overflow-hidden rounded-xl bg-neutral-50">
+      <div className="flex items-center justify-end px-2 py-1">
+        <Button
+          type="text"
+          size="small"
+          icon={copied ? <CheckOutlined /> : <CopyOutlined />}
+          className="text-neutral-600 hover:bg-black/5! hover:text-neutral-800!"
+          onClick={() => {
+            void onCopy();
+          }}
+        >
+          {copied ? "已复制" : "复制"}
+        </Button>
+      </div>
+      <pre className="m-0 overflow-x-auto p-3 text-[13px] text-neutral-800">{props.children}</pre>
+    </div>
+  );
+}
+
 export default function StreamMessage(props: StreamMessageProps) {
   return (
-    <div className="rounded-2xl border border-[var(--ds-border)] bg-neutral-50/80 px-4 py-2.5 text-[15px] leading-relaxed text-neutral-800">
-      <div className="prose prose-sm max-w-none break-words prose-neutral prose-pre:my-2 prose-pre:rounded-lg prose-pre:border prose-pre:border-[var(--ds-border)] prose-pre:bg-neutral-950 prose-pre:p-3 prose-code:before:content-none prose-code:after:content-none">
+    <div className="rounded-2xl px-4 py-2.5 text-[15px] leading-relaxed text-neutral-800">
+      <div className="prose prose-sm max-w-none break-words prose-neutral prose-code:before:content-none prose-code:after:content-none">
         <ReactMarkdown
           remarkPlugins={[remarkGfm, remarkMath]}
           rehypePlugins={[rehypeKatex, rehypeHighlight]}
           components={{
+            pre: ({ children }) => <MarkdownPreBlock>{children}</MarkdownPreBlock>,
             table: ({ children }) => (
               <div className="my-2 overflow-x-auto rounded-lg border border-[var(--ds-border)]">
                 <table className="w-full border-collapse text-sm">{children}</table>