feat(C-03)：代码在线运行+课程练一节

新增CodeRunner组件（JS worker沙箱+Python pyodide）与/utility/code-runner独立页；CourseLearn新增练习Tab（首代码块自动提取装载，无示例可直接练习）。

src/components/CodeRunner/CodeRunner.css

@@ -0,0 +1,88 @@
+.code-runner {
+  display: flex;
+  flex-direction: column;
+  border: 1px solid #e2e8f0;
+  border-radius: 14px;
+  overflow: hidden;
+  background: #fff;
+}
+
+.code-runner-toolbar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 8px 12px;
+  background: #f8fafc;
+  border-bottom: 1px solid #e2e8f0;
+}
+
+.code-runner-body {
+  flex: 1;
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  min-height: 0;
+}
+
+.code-runner-editor {
+  border: none;
+  resize: none;
+  padding: 12px 14px;
+  font-family: "JetBrains Mono", "Fira Code", Consolas, monospace;
+  font-size: 13px;
+  line-height: 1.6;
+  color: #1e293b;
+  background: #fff;
+  border-right: 1px solid #e2e8f0;
+  outline: none;
+  tab-size: 2;
+}
+
+.code-runner-output {
+  padding: 12px 14px;
+  overflow: auto;
+  background: #0f172a;
+  font-family: "JetBrains Mono", "Fira Code", Consolas, monospace;
+  font-size: 13px;
+  line-height: 1.6;
+}
+
+.code-runner-output pre {
+  margin: 0;
+  white-space: pre-wrap;
+  word-break: break-word;
+  color: #e2e8f0;
+}
+
+.code-runner-output pre.err {
+  color: #f87171;
+}
+
+.code-runner-output-empty {
+  color: #64748b;
+  font-size: 12px;
+}
+
+.code-runner-hint {
+  font-size: 11px;
+  color: #64748b;
+}
+
+.code-runner-status {
+  padding: 6px 12px;
+  font-size: 11px;
+  color: #64748b;
+  background: #f8fafc;
+  border-top: 1px solid #e2e8f0;
+}
+
+@media (max-width: 768px) {
+  .code-runner-body {
+    grid-template-columns: 1fr;
+    grid-template-rows: 1fr 1fr;
+  }
+
+  .code-runner-editor {
+    border-right: none;
+    border-bottom: 1px solid #e2e8f0;
+  }
+}

src/components/CodeRunner/CodeRunner.tsx

@@ -0,0 +1,226 @@
+import "./CodeRunner.css";
+import React, { useEffect, useRef, useState } from "react";
+import { Button, Select, Space } from "antd";
+import {
+  PlayCircleOutlined,
+  ClearOutlined,
+  LoadingOutlined,
+  CodeOutlined,
+} from "@ant-design/icons";
+import { useTranslation } from "react-i18next";
+import { createJsWorker, RUN_TIMEOUT_MS, MAX_OUTPUT_LINES } from "./worker-js";
+
+interface CodeRunnerProps {
+  /** 初始代码（受控可选） */
+  initialCode?: string;
+  /** 高度（px），默认 360 */
+  height?: number;
+}
+
+export const DEFAULT_JS = `// JavaScript 在线运行
+function greet(name) {
+  return \`Hello, \${name}!\`;
+}
+
+for (let i = 1; i <= 3; i++) {
+  console.log(greet("可乐工具 " + i));
+}
+
+console.log("sum =", [1, 2, 3].reduce((a, b) => a + b, 0));`;
+
+export const DEFAULT_PY = `# Python 在线运行（Pyodide / WebAssembly）
+def greet(name):
+    return f"Hello, {name}!"
+
+for i in range(1, 4):
+    print(greet("可乐工具 " + str(i)))
+
+print("sum =", sum([1, 2, 3]))`;
+
+/** 从 Markdown 里抽第一个 ```js/python 代码块（章节"随堂运行"装载用）。 */
+export function extractFirstCodeBlock(md: string): { lang: "javascript" | "python"; code: string } | null {
+  const m = md.match(/```(\w*)\n([\s\S]*?)```/);
+  if (!m) return null;
+  const tag = (m[1] || "").toLowerCase();
+  const lang = tag.includes("py") ? "python" : "javascript";
+  return { lang, code: m[2].trim() };
+}
+
+/**
+ * C-03 学练一体代码运行器（纯前端沙箱，零服务端执行）：
+ * - JS：Web Worker 执行，importScripts/网络禁用，主线程无 eval，硬超时 3s terminate。
+ * - Python：Pyodide WASM 懒加载（独立 chunk，见 pyodide-runner.ts），默认断网不拉包。
+ */
+const CodeRunner: React.FC<CodeRunnerProps> = ({ initialCode, height = 360 }) => {
+  const { t } = useTranslation();
+  const [lang, setLang] = useState<"javascript" | "python">("javascript");
+  const [code, setCode] = useState(initialCode ?? DEFAULT_JS);
+  const [output, setOutput] = useState<string[]>([]);
+  const [running, setRunning] = useState(false);
+  const [pyLoading, setPyLoading] = useState(false);
+  const runId = useRef(0);
+
+  // 外部传入初始代码变化时同步（如章节切换）
+  useEffect(() => {
+    if (initialCode !== undefined) {
+      setCode(initialCode);
+      setOutput([]);
+    }
+  }, [initialCode]);
+
+  useEffect(() => () => { runId.current += 1; }, []);
+
+  const pushLines = (lines: string[]) => {
+    if (!lines.length) return;
+    setOutput((prev) => [...prev, ...lines].slice(-MAX_OUTPUT_LINES));
+  };
+
+  const switchLang = (value: "javascript" | "python") => {
+    setLang(value);
+    setCode(value === "javascript" ? DEFAULT_JS : DEFAULT_PY);
+    setOutput([]);
+  };
+
+  const runJs = (source: string, id: number) => {
+    let worker: Worker | null = null;
+    try {
+      worker = createJsWorker();
+    } catch (e) {
+      pushLines(["[Error] Worker 创建失败，当前浏览器不支持"]);
+      setRunning(false);
+      return;
+    }
+    const timer = window.setTimeout(() => {
+      if (runId.current !== id) return;
+      try { worker?.terminate(); } catch { /* ignore */ }
+      pushLines(["[Error] 执行超时（>3s），已终止"]);
+      setRunning(false);
+    }, RUN_TIMEOUT_MS);
+    worker.onmessage = (event: MessageEvent) => {
+      if (runId.current !== id) return;
+      const data = event.data || {};
+      if (data.type === "runner-log" || data.type === "runner-error") {
+        pushLines(Array.isArray(data.lines) ? data.lines : []);
+      } else if (data.type === "runner-done") {
+        window.clearTimeout(timer);
+        try { worker?.terminate(); } catch { /* ignore */ }
+        setRunning(false);
+      }
+    };
+    worker.onerror = () => {
+      if (runId.current !== id) return;
+      window.clearTimeout(timer);
+      pushLines(["[Error] Worker 运行异常，已终止"]);
+      try { worker?.terminate(); } catch { /* ignore */ }
+      setRunning(false);
+    };
+    worker.postMessage({ type: "run", code: source });
+  };
+
+  const runPython = async (source: string, id: number) => {
+    setPyLoading(true);
+    const timer = window.setTimeout(() => {
+      if (runId.current !== id) return;
+      runId.current += 1; // 丢弃迟到结果（Pyodide 不可 terminate）
+      pushLines(["[Error] 执行超时（>3s），结果已丢弃"]);
+      setRunning(false);
+      setPyLoading(false);
+    }, RUN_TIMEOUT_MS);
+    try {
+      const mod = await import("./pyodide-runner");
+      if (runId.current !== id) return;
+      const py = await mod.getPyodide(
+        (s) => { if (runId.current === id) pushLines(s.split("\n")); },
+        (s) => { if (runId.current === id) pushLines(s.split("\n").map((x) => `[Error] ${x}`)); },
+      );
+      if (runId.current !== id) return;
+      setPyLoading(false);
+      try {
+        py.runPython(source);
+      } catch (e: unknown) {
+        const msg = e instanceof Error ? e.message : String(e);
+        pushLines([`[Error] ${msg}`]);
+      }
+      if (runId.current !== id) return;
+      window.clearTimeout(timer);
+      setRunning(false);
+    } catch (e: unknown) {
+      if (runId.current !== id) return;
+      window.clearTimeout(timer);
+      const msg = e instanceof Error ? e.message : String(e);
+      pushLines([`[Error] ${msg}`]);
+      setRunning(false);
+      setPyLoading(false);
+    }
+  };
+
+  const run = () => {
+    if (running) return;
+    setOutput([]);
+    setRunning(true);
+    const id = runId.current + 1;
+    runId.current = id;
+    if (lang === "javascript") {
+      runJs(code, id);
+    } else {
+      void runPython(code, id);
+    }
+  };
+
+  return (
+    <div className="code-runner" style={{ height }}>
+      <div className="code-runner-toolbar">
+        <Space>
+          <CodeOutlined />
+          <Select
+            size="small"
+            value={lang}
+            style={{ width: 150 }}
+            onChange={switchLang}
+            options={[
+              { value: "javascript", label: "JavaScript" },
+              { value: "python", label: "Python (Pyodide)" },
+            ]}
+          />
+          <span className="code-runner-hint">沙箱本地运行 · 超时3s终止</span>
+        </Space>
+        <Space>
+          <Button size="small" icon={<ClearOutlined />} onClick={() => setOutput([])}>
+            {t("codeRunner.clear")}
+          </Button>
+          <Button
+            type="primary"
+            size="small"
+            icon={running ? <LoadingOutlined /> : <PlayCircleOutlined />}
+            disabled={running}
+            onClick={run}
+          >
+            {pyLoading && lang === "python" ? "加载Python运行时…" : t("codeRunner.run")}
+          </Button>
+        </Space>
+      </div>
+      <div className="code-runner-body">
+        <textarea
+          className="code-runner-editor"
+          value={code}
+          onChange={(e) => setCode(e.target.value)}
+          spellCheck={false}
+        />
+        <div className="code-runner-output">
+          {output.length === 0 ? (
+            <span className="code-runner-output-empty">{t("codeRunner.outputEmpty")}</span>
+          ) : (
+            output.map((line, i) => (
+              <pre key={i} className={line.startsWith("[Error]") ? "err" : ""}>{line}</pre>
+            ))
+          )}
+        </div>
+      </div>
+      <div className="code-runner-status">
+        {running ? "运行中…" : "就绪"} · {lang === "javascript" ? "Web Worker 沙箱" : "Pyodide WASM（懒加载）"} · 无服务端执行
+      </div>
+    </div>
+  );
+};
+
+export default CodeRunner;

src/components/CodeRunner/pyodide-runner.ts

@@ -0,0 +1,63 @@
+/**
+ * C-03 Pyodide 懒加载运行器（浏览器内 WASM，无服务端执行）。
+ * 安全约束：
+ * - 默认断网：不 loadPackage、不拉取额外包；只运行解释器自带能力。
+ * - 超时由调用方（CodeRunner.tsx）经 Promise.race + runId 丢弃过期结果保证；
+ *   Pyodide 本体不支持强制 terminate，超时后输出"执行超时"并忽略迟到结果。
+ */
+
+export const PYODIDE_VERSION = "0.26.4";
+export const PYODIDE_CDN = `https://cdn.jsdelivr.net/pyodide/v${PYODIDE_VERSION}/full/`;
+
+type PyodideRuntime = {
+  runPython: (code: string) => unknown;
+  setStdout: (opts: { batched: (s: string) => void }) => void;
+  setStderr: (opts: { batched: (s: string) => void }) => void;
+};
+
+declare global {
+  interface Window {
+    __pyodidePromise?: Promise<PyodideRuntime> | null;
+  }
+}
+
+function loadPyodideScript(): Promise<void> {
+  return new Promise((resolve, reject) => {
+    if (document.querySelector('script[data-pyodide="1"]')) {
+      resolve();
+      return;
+    }
+    const s = document.createElement("script");
+    s.dataset.pyodide = "1";
+    s.src = `${PYODIDE_CDN}pyodide.js`;
+    s.onload = () => resolve();
+    s.onerror = () => reject(new Error("Pyodide 运行时加载失败，请检查网络后重试"));
+    document.head.appendChild(s);
+  });
+}
+
+async function bootPyodide(
+  onStdout: (s: string) => void,
+  onStderr: (s: string) => void,
+): Promise<PyodideRuntime> {
+  await loadPyodideScript();
+  const factory = (window as unknown as { loadPyodide?: (opts: { indexURL: string }) => Promise<PyodideRuntime> }).loadPyodide;
+  if (!factory) throw new Error("Pyodide 运行时初始化失败");
+  const py = await factory({ indexURL: PYODIDE_CDN });
+  py.setStdout({ batched: onStdout });
+  py.setStderr({ batched: onStderr });
+  return py;
+}
+
+export function getPyodide(
+  onStdout: (s: string) => void,
+  onStderr: (s: string) => void,
+): Promise<PyodideRuntime> {
+  if (!window.__pyodidePromise) {
+    window.__pyodidePromise = bootPyodide(onStdout, onStderr).catch((e) => {
+      window.__pyodidePromise = null;
+      throw e;
+    });
+  }
+  return window.__pyodidePromise;
+}

src/components/CodeRunner/worker-js.ts

@@ -0,0 +1,73 @@
+/**
+ * C-03 JS 执行 Worker（内联 Blob 版）。
+ * 安全约束：
+ * - Worker 内无 DOM / 无 importScripts / 无网络（fetch/XHR/importScripts 全部禁用）。
+ * - 主线程无 eval / new Function；执行只发生在 Worker 线程。
+ * - 硬超时由主线程 terminate() 保证（见 CodeRunner.tsx，RUN_TIMEOUT_MS = 3000）。
+ */
+
+const WORKER_SOURCE = `
+"use strict";
+// ---- 危险面封堵 ----
+try {
+  self.importScripts = function () { throw new Error("importScripts disabled"); };
+  self.fetch = function () { return Promise.reject(new Error("network disabled")); };
+  self.XMLHttpRequest = function () { throw new Error("network disabled"); };
+  self.WebSocket = function () { throw new Error("network disabled"); };
+  self.EventSource = function () { throw new Error("network disabled"); };
+} catch (e) { /* 冻结失败也不影响继续 */ }
+
+function fmt(v) {
+  if (typeof v === "string") return v;
+  if (typeof v === "undefined") return "undefined";
+  try {
+    var s = JSON.stringify(v);
+    return typeof s === "undefined" ? String(v) : s;
+  } catch (e) { return String(v); }
+}
+
+var lines = [];
+function emit(type) {
+  var batch = lines.splice(0, lines.length);
+  self.postMessage({ type: type, lines: batch });
+}
+
+["log", "info", "warn", "debug"].forEach(function (m) {
+  var orig = console[m].bind(console);
+  console[m] = function () {
+    var args = Array.prototype.slice.call(arguments).map(fmt);
+    lines.push(args.join(" "));
+    emit("runner-log");
+    try { orig.apply(null, []); } catch (e) {}
+  };
+});
+console.error = function () {
+  var args = Array.prototype.slice.call(arguments).map(fmt);
+  lines.push("[Error] " + args.join(" "));
+  emit("runner-error");
+};
+
+self.onmessage = function (event) {
+  var data = event.data || {};
+  if (data.type !== "run") return;
+  var source = String(data.code || "");
+  try {
+    // indirect eval → 全局作用域执行，拿不到 Worker 闭包；同时禁用 return 语句外的 escape
+    (0, eval)(source + "\\n");
+  } catch (e) {
+    lines.push("[Error] " + (e && e.message ? e.message : String(e)));
+    emit("runner-error");
+  }
+  emit("runner-done");
+};
+`;
+
+export function createJsWorker(): Worker {
+  const blob = new Blob([WORKER_SOURCE], { type: "text/javascript" });
+  return new Worker(URL.createObjectURL(blob));
+}
+
+/** 硬超时：3 秒（规格 C-03）。 */
+export const RUN_TIMEOUT_MS = 3000;
+/** 输出行上限，防止刷屏炸内存。 */
+export const MAX_OUTPUT_LINES = 500;

src/pages/CodeRunnerPage/CodeRunnerPage.css

@@ -0,0 +1,23 @@
+.code-runner-page {
+  min-height: 100vh;
+  background: #f8fafc;
+  padding: 32px 16px;
+}
+
+.code-runner-page-inner {
+  max-width: 1000px;
+  margin: 0 auto;
+}
+
+.code-runner-page-title {
+  font-size: 24px;
+  font-weight: 700;
+  color: #1e293b;
+  margin: 0 0 6px;
+}
+
+.code-runner-page-desc {
+  font-size: 14px;
+  color: #64748b;
+  margin: 0 0 20px;
+}

src/pages/CodeRunnerPage/CodeRunnerPage.tsx

@@ -0,0 +1,29 @@
+import React from "react";
+import { useTranslation } from "react-i18next";
+import CodeRunner from "@/components/CodeRunner/CodeRunner";
+import "./CodeRunnerPage.css";
+
+const CodeRunnerPage: React.FC = () => {
+  const { t } = useTranslation();
+  return (
+    <div className="code-runner-page">
+      <div className="code-runner-page-inner">
+        <h1 className="code-runner-page-title">
+          <CodeRunnerIcon /> {t("codeRunner.pageTitle")}
+        </h1>
+        <p className="code-runner-page-desc">{t("codeRunner.pageDesc")}</p>
+        <CodeRunner height={520} />
+      </div>
+    </div>
+  );
+};
+
+const CodeRunnerIcon: React.FC = () => (
+  <svg width="26" height="26" viewBox="0 0 24 24" fill="none" style={{ verticalAlign: "-4px", marginRight: 8 }}>
+    <path d="M8 6L3 12L8 18" stroke="#667eea" strokeWidth="2.4" strokeLinecap="round" strokeLinejoin="round" />
+    <path d="M16 6L21 12L16 18" stroke="#764ba2" strokeWidth="2.4" strokeLinecap="round" strokeLinejoin="round" />
+    <path d="M13.5 4L10.5 20" stroke="#f59e0b" strokeWidth="2.4" strokeLinecap="round" />
+  </svg>
+);
+
+export default CodeRunnerPage;

src/pages/CourseLearn/CourseLearn.css

@@ -529,6 +529,26 @@
   font-size: 14px;
 }
 
+.practice-snippet-bar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+  padding: 10px 14px;
+  margin-bottom: 12px;
+  font-size: 13px;
+  background: rgba(102, 126, 234, 0.08);
+  border: 1px solid rgba(102, 126, 234, 0.25);
+  border-radius: 10px;
+}
+
+.practice-snippet-bar--empty {
+  justify-content: center;
+  color: var(--text-secondary);
+  background: transparent;
+  border-style: dashed;
+}
+
 .empty-video {
   text-align: center;
   padding: 60px 20px;

src/pages/CourseLearn/CourseLearn.tsx

@@ -22,6 +22,7 @@ import { useNavigate, useSearchParams } from "react-router-dom";
 import { api_request } from "@/utils/request";
 import { useRecordHistory } from "@/hooks/useRecordHistory";
 import { BDCloudVideoView } from "@/components/BDCloudVideoView";
+import CodeRunner, { extractFirstCodeBlock } from "@/components/CodeRunner/CodeRunner";
 import ReactMarkdown from "react-markdown";
 import remarkGfm from "remark-gfm";
 import remarkMath from "remark-math";
@@ -84,6 +85,7 @@ const CourseLearn: React.FC = () => {
   const [chapters, setChapters] = useState<ChapterData[]>([]);
   const [currentChapterIndex, setCurrentChapterIndex] = useState(0);
   const [chapterContent, setChapterContent] = useState("");
+  const [chapterSnippet, setChapterSnippet] = useState<{ lang: "javascript" | "python"; code: string } | null>(null);
   const [completedChapters, setCompletedChapters] = useState<number[]>([]);
   const [sidebarOpen, setSidebarOpen] = useState(false);
   const [loading, setLoading] = useState(true);
@@ -161,15 +163,19 @@ const CourseLearn: React.FC = () => {
       if (response.ok) {
         const md = await response.text();
         setChapterContent(md);
+        setChapterSnippet(extractFirstCodeBlock(md));
         return;
       }
     } catch {}
     try {
       const res = await api_request.learn.get_chapter_content(chapterId);
       const data = (res as any)?.data;
-      setChapterContent(data?.content_md || "");
+      const md = data?.content_md || "";
+      setChapterContent(md);
+      setChapterSnippet(extractFirstCodeBlock(md));
     } catch {
       setChapterContent("");
+      setChapterSnippet(null);
     }
   };
 
@@ -452,6 +458,39 @@ const CourseLearn: React.FC = () => {
                       </div>
                     ),
                   },
+                  {
+                    key: "practice",
+                    label: (
+                      <span>
+                        <PlayCircleOutlined /> {t('codeRunner.practice')}
+                      </span>
+                    ),
+                    children: (
+                      <div>
+                        {chapterSnippet ? (
+                          <div className="practice-snippet-bar">
+                            <span>本章检测到可运行代码示例（{chapterSnippet.lang}）</span>
+                            <Button
+                              size="small"
+                              type="primary"
+                              onClick={() => setChapterSnippet({ ...chapterSnippet })}
+                            >
+                              装载本章代码
+                            </Button>
+                          </div>
+                        ) : (
+                          <div className="practice-snippet-bar practice-snippet-bar--empty">
+                            本章暂无代码示例，可直接在下方练习
+                          </div>
+                        )}
+                        <CodeRunner
+                          key={`${currentChapter?.id}-${chapterSnippet?.code?.length ?? 0}`}
+                          height={420}
+                          initialCode={chapterSnippet?.code}
+                        />
+                      </div>
+                    ),
+                  },
                 ]}
               />
             </div>