diff --git a/scripts/dev-artifact-publish.mjs b/scripts/dev-artifact-publish.mjs
index dde01192..1b7a2db6 100644
--- a/scripts/dev-artifact-publish.mjs
+++ b/scripts/dev-artifact-publish.mjs
@@ -303,6 +303,7 @@ function runtimeScriptBase64() {
 import { createServer } from "node:http";
 import http from "node:http";
 import { spawn } from "node:child_process";
+import { randomBytes, timingSafeEqual } from "node:crypto";
 import { chmodSync, existsSync, lstatSync, mkdirSync, symlinkSync } from "node:fs";
 import { readFile, stat } from "node:fs/promises";
 import path from "node:path";
@@ -317,6 +318,14 @@ const cloudApiProxyTimeoutMs = parseTimeout(process.env.HWLAB_CLOUD_WEB_PROXY_TI
   min: 1000,
   max: 300000
 });
+const authUsername = nonEmptyEnv("HWLAB_CLOUD_WEB_AUTH_USERNAME", "admin");
+const authPassword = nonEmptyEnv("HWLAB_CLOUD_WEB_AUTH_PASSWORD", "hwlab2026");
+const authSessionTtlMs = parseTimeout(process.env.HWLAB_CLOUD_WEB_AUTH_SESSION_TTL_MS, 12 * 60 * 60 * 1000, {
+  min: 60 * 1000,
+  max: 7 * 24 * 60 * 60 * 1000
+});
+const authCookieName = "hwlab_cloud_web_session";
+const authSessions = new Map();
 const readOnlyRpcMethods = new Set([
   "system.health",
   "cloud.adapter.describe",
@@ -366,6 +375,11 @@ function sendJson(response, statusCode, body) {
   response.end(payload);
 }
 
+function nonEmptyEnv(name, fallback) {
+  const value = process.env[name];
+  return typeof value === "string" && value.trim() ? value.trim() : fallback;
+}
+
 function healthPayload() {
   return {
     serviceId,
@@ -388,6 +402,114 @@ function runNodeEntrypoint(file) {
   });
 }
 
+function cookieValue(request, name) {
+  const raw = request.headers.cookie || "";
+  for (const part of raw.split(";")) {
+    const [key, ...rest] = part.trim().split("=");
+    if (key === name) return decodeURIComponent(rest.join("=") || "");
+  }
+  return "";
+}
+
+function authCookie(token, expiresAt) {
+  const maxAgeSeconds = Math.max(0, Math.floor((expiresAt - Date.now()) / 1000));
+  return authCookieName + "=" + encodeURIComponent(token) + "; Path=/; HttpOnly; SameSite=Lax; Max-Age=" + maxAgeSeconds;
+}
+
+function clearAuthCookie() {
+  return authCookieName + "=; Path=/; HttpOnly; SameSite=Lax; Max-Age=0";
+}
+
+function activeAuthSession(request) {
+  const token = cookieValue(request, authCookieName);
+  if (!token) return null;
+  const session = authSessions.get(token);
+  if (!session) return null;
+  if (session.expiresAt <= Date.now()) {
+    authSessions.delete(token);
+    return null;
+  }
+  return { token, ...session };
+}
+
+function cleanupExpiredAuthSessions() {
+  const now = Date.now();
+  for (const [token, session] of authSessions) {
+    if (session.expiresAt <= now) authSessions.delete(token);
+  }
+}
+
+function constantTimeEquals(a, b) {
+  const left = Buffer.from(String(a));
+  const right = Buffer.from(String(b));
+  if (left.length !== right.length) return false;
+  return timingSafeEqual(left, right);
+}
+
+async function handleCloudWebAuth(request, response, url) {
+  if (url.pathname === "/auth/session" && request.method === "GET") {
+    const session = activeAuthSession(request);
+    sendJson(response, 200, session ? {
+      authenticated: true,
+      user: { username: session.username },
+      expiresAt: new Date(session.expiresAt).toISOString()
+    } : { authenticated: false });
+    return true;
+  }
+
+  if (url.pathname === "/auth/login" && request.method === "POST") {
+    let body = {};
+    try {
+      body = JSON.parse(await readRequestBody(request) || "{}");
+    } catch {
+      sendJson(response, 400, { authenticated: false, error: "invalid_request" });
+      return true;
+    }
+    const username = typeof body.username === "string" ? body.username.trim() : "";
+    const password = typeof body.password === "string" ? body.password : "";
+    if (!constantTimeEquals(username, authUsername) || !constantTimeEquals(password, authPassword)) {
+      sendJson(response, 401, { authenticated: false, error: "invalid_credentials" });
+      return true;
+    }
+    cleanupExpiredAuthSessions();
+    const token = randomBytes(32).toString("hex");
+    const expiresAt = Date.now() + authSessionTtlMs;
+    authSessions.set(token, { username: authUsername, expiresAt });
+    const payload = JSON.stringify({
+      authenticated: true,
+      user: { username: authUsername },
+      expiresAt: new Date(expiresAt).toISOString()
+    }, null, 2);
+    response.writeHead(200, {
+      "content-type": "application/json; charset=utf-8",
+      "content-length": Buffer.byteLength(payload),
+      "set-cookie": authCookie(token, expiresAt)
+    });
+    response.end(payload);
+    return true;
+  }
+
+  if (url.pathname === "/auth/logout" && request.method === "POST") {
+    const session = activeAuthSession(request);
+    if (session) authSessions.delete(session.token);
+    const payload = JSON.stringify({ authenticated: false }, null, 2);
+    response.writeHead(200, {
+      "content-type": "application/json; charset=utf-8",
+      "content-length": Buffer.byteLength(payload),
+      "set-cookie": clearAuthCookie()
+    });
+    response.end(payload);
+    return true;
+  }
+
+  if (url.pathname.startsWith("/auth/")) {
+    sendJson(response, 404, { authenticated: false, error: "not_found" });
+    return true;
+  }
+
+  return false;
+}
+
 async function readRequestBody(request) {
   let body = "";
   for await (const chunk of request) {
@@ -520,11 +642,22 @@ async function serveCloudWeb() {
       sendJson(response, 200, healthPayload());
       return;
     }
+    if (await handleCloudWebAuth(request, response, url)) {
+      return;
+    }
 
     if (
       (request.method === "GET" && (url.pathname === "/v1" || url.pathname === "/v1/m3/status" || url.pathname.startsWith("/v1/"))) ||
       (request.method === "POST" && (url.pathname === "/json-rpc" || url.pathname === "/v1/agent/chat" || url.pathname === "/v1/m3/io"))
     ) {
+      if (!activeAuthSession(request)) {
+        sendJson(response, 401, {
+          status: "failed",
+          error: "auth_required",
+          serviceId
+        });
+        return;
+      }
       await proxyCloudApi(request, response, url);
       return;
     }
diff --git a/scripts/src/dev-cloud-workbench-smoke-lib.mjs b/scripts/src/dev-cloud-workbench-smoke-lib.mjs
index bec2003f..88777637 100644
--- a/scripts/src/dev-cloud-workbench-smoke-lib.mjs
+++ b/scripts/src/dev-cloud-workbench-smoke-lib.mjs
@@ -72,6 +72,7 @@ const readOnlyRpcMethods = Object.freeze([
 const requiredWebAssets = Object.freeze([
   "index.html",
   "styles.css",
+  "auth.mjs",
   "app.mjs",
   "code-agent-facts.mjs",
   "code-agent-status.mjs",
@@ -86,9 +87,10 @@ const requiredWebAssets = Object.freeze([
   "third_party/marked/LICENSE"
 ]);
 
-const liveIdentityWebAssets = Object.freeze(["index.html", "styles.css", "app.mjs", "code-agent-facts.mjs", "code-agent-status.mjs", "live-status.mjs", "wiring-status.mjs"]);
+const liveIdentityWebAssets = Object.freeze(["index.html", "styles.css", "auth.mjs", "app.mjs", "code-agent-facts.mjs", "code-agent-status.mjs", "live-status.mjs", "wiring-status.mjs"]);
 
 const chineseWorkbenchLabels = Object.freeze([
+  "云工作台登录",
   "HWLAB 云工作台",
   "硬件资源",
   "Agent 对话",
@@ -98,6 +100,11 @@ const chineseWorkbenchLabels = Object.freeze([
   "使用说明"
 ]);
 
+const defaultAuthCredentials = Object.freeze({
+  username: "admin",
+  password: "hwlab2026"
+});
+
 const defaultHomepageForbiddenTerms = Object.freeze([
   "Gate",
   "诊断",
@@ -370,6 +377,7 @@ export async function runDevCloudWorkbenchTimeoutFixtureSmoke(options = {}) {
 export async function runDevCloudWorkbenchSmoke(argv = []) {
   const args = parseSmokeArgs(argv);
   if (args.mode === "live") return runLiveSmoke(args);
+  if (args.mode === "auth-fixture") return runDevCloudWorkbenchAuthFixtureSmoke();
   if (args.mode === "local-agent-timeout-fixture") return runDevCloudWorkbenchTimeoutFixtureSmoke();
   if (args.mode === "dom-only") return runLiveDomOnlySmoke(args);
   if (args.mode === "m3-status-fixture") return runM3StatusFixtureSmoke();
@@ -440,6 +448,8 @@ export function parseSmokeArgs(argv) {
       args.mode = "local-agent-fixture";
     } else if (arg === "--quick-prompts-fixture") {
       args.mode = "quick-prompts-fixture";
+    } else if (arg === "--auth-fixture") {
+      args.mode = "auth-fixture";
     } else if (arg === "--local-agent-timeout-fixture") {
       args.mode = "local-agent-timeout-fixture";
     } else if (arg === "--url") {
@@ -476,9 +486,14 @@ function runStaticSmoke() {
     evidence: requiredWebAssets.map((file) => `web/hwlab-cloud-web/${file}`)
   });
 
-  addCheck(checks, blockers, "default-workbench-shell", hasDefaultWorkbench(files), "Default route is the VS Code-style Cloud Workbench.", {
+  addCheck(checks, blockers, "default-login-entry", hasDefaultLoginEntry(files, artifactPublisher), "Default 16666 route shows the Chinese login page before the Cloud Workbench is exposed.", {
     blocker: "runtime_blocker",
-    evidence: ["workspace view is visible by default", "Gate view is hidden by default", ...workbenchMarkers]
+    evidence: ["云工作台登录", "账号或密码不正确，请重新输入。", "data-app-shell hidden", "auth.mjs", "HWLAB_CLOUD_WEB_AUTH_USERNAME", "HWLAB_CLOUD_WEB_AUTH_PASSWORD"]
+  });
+
+  addCheck(checks, blockers, "default-workbench-shell", hasDefaultWorkbench(files), "Authenticated route is the VS Code-style Cloud Workbench.", {
+    blocker: "runtime_blocker",
+    evidence: ["workspace view exists behind login", "Gate view is hidden by default after auth", ...workbenchMarkers]
   });
 
   addCheck(checks, blockers, "secondary-gate-status-help", secondaryViewsAreNotDefault(files), "Gate/status/diagnostics/help surfaces are not accepted as the default homepage.", {
@@ -1657,6 +1672,7 @@ function readStaticFiles() {
   return {
     html: readText("web/hwlab-cloud-web/index.html"),
     styles: readText("web/hwlab-cloud-web/styles.css"),
+    auth: readText("web/hwlab-cloud-web/auth.mjs"),
     app: readText("web/hwlab-cloud-web/app.mjs"),
     codeAgentFacts: readText("web/hwlab-cloud-web/code-agent-facts.mjs"),
     codeAgentStatus: readText("web/hwlab-cloud-web/code-agent-status.mjs"),
@@ -1902,15 +1918,50 @@ function assetsExist() {
   return requiredWebAssets.every((file) => fs.existsSync(path.join(webRoot, file)));
 }
 
+function hasDefaultLoginEntry({ html, app, auth, styles }, artifactPublisher = "") {
+  const loginShellTag = html.match(/<section\b[^>]*\bid=["']login-shell["'][^>]*>/u)?.[0] ?? "";
+  const appShellTag = html.match(/<main\b[^>]*\bdata-app-shell\b[^>]*>/u)?.[0] ?? "";
+  const loginHtml = html.match(/<section\b[^>]*\bid=["']login-shell["'][\s\S]*?<\/section>/u)?.[0] ?? "";
+  const defaultShellText = visibleTextFromHtml(loginHtml);
+  const authSource = `${auth}\n${app}\n${styles}\n${artifactPublisher}`;
+  return (
+    loginShellTag.includes("data-auth-login") &&
+    !/\bhidden\b/u.test(loginShellTag) &&
+    /\bhidden\b/u.test(appShellTag) &&
+    /data-auth-state=["']checking["']/u.test(html) &&
+    ["云工作台登录", "请输入账号和密码。", "用户名", "密码", "登录"].every((term) => defaultShellText.includes(term)) &&
+    !defaultShellText.includes("Gate") &&
+    !defaultShellText.includes("诊断") &&
+    !defaultShellText.includes("验收") &&
+    !defaultShellText.includes("后厨") &&
+    /DEFAULT_AUTH_USERNAME\s*=\s*["']admin["']/u.test(auth) &&
+    /DEFAULT_AUTH_PASSWORD\s*=\s*["']hwlab2026["']/u.test(auth) &&
+    /HWLAB_CLOUD_WEB_CONFIG\?\.auth/u.test(auth) &&
+    /AUTH_STORAGE_KEY\s*=\s*["']hwlab\.cloudWorkbench\.auth\.v1["']/u.test(auth) &&
+    /账号或密码不正确，请重新输入。/u.test(auth) &&
+    /ensureWorkbenchAuth/u.test(app) &&
+    /await\s+ensureWorkbenchAuth/u.test(app) &&
+    /initWorkbenchLogout/u.test(app) &&
+    /HWLAB_CLOUD_WEB_AUTH_USERNAME/u.test(authSource) &&
+    /HWLAB_CLOUD_WEB_AUTH_PASSWORD/u.test(authSource) &&
+    /auth_required/u.test(authSource) &&
+    /\.login-shell\s*\{[^}]*height:\s*100dvh;[^}]*overflow:\s*hidden;/su.test(styles) &&
+    /\.login-panel\s*\{[^}]*width:\s*min\(100%,\s*360px\);/su.test(styles) &&
+    /\.workbench-shell\[hidden\]/u.test(styles)
+  );
+}
+
 function hasDefaultWorkbench({ html, app }) {
   const workspaceTag = firstTagForDataView(html, "workspace");
   const gateTag = firstTagForDataView(html, "gate");
+  const appShellTag = html.match(/<main\b[^>]*\bdata-app-shell\b[^>]*>/u)?.[0] ?? "";
   return (
     labelsPresent(html, workbenchMarkers) &&
     /<title>\s*HWLAB 云工作台\s*<\/title>/u.test(html) &&
     /data-route=["']workspace["']/u.test(html) &&
     workspaceTag !== null &&
     !/\bhidden\b/u.test(workspaceTag) &&
+    /\bhidden\b/u.test(appShellTag) &&
     gateTag !== null &&
     /\bhidden\b/u.test(gateTag) &&
     finalRouteFallback(app) === "workspace"
@@ -2975,6 +3026,9 @@ async function inspectLiveDom(url, options = {}) {
     const page = await browser.newPage({ viewport: { width: 1366, height: 768 } });
     const postGuard = options.noCodeAgentPost ? await installNoCodeAgentPostGuard(page) : null;
     await page.goto(url, { waitUntil: "domcontentloaded", timeout: 8000 });
+    const login = await inspectLoginPage(page);
+    await loginWithDefaultCredentials(page);
+    await page.locator("#command-input").waitFor({ state: "visible", timeout: 12000 });
     const dom = await page.evaluate(async (forbiddenTerms) => {
       const workspace = document.querySelector('[data-view="workspace"]');
       const gate = document.querySelector('[data-view="gate"]');
@@ -3075,6 +3129,9 @@ async function inspectLiveDom(url, options = {}) {
       };
     }, [...defaultHomepageForbiddenTerms]);
     const pass =
+      login.loginVisible &&
+      login.workbenchHidden &&
+      login.copyOk &&
       dom.title === "HWLAB 云工作台" &&
       dom.bodyOverflow === "hidden" &&
       dom.htmlOverflow === "hidden" &&
@@ -3114,6 +3171,8 @@ async function inspectLiveDom(url, options = {}) {
       status: pass ? "pass" : "blocked",
       summary: pass ? "Browser DOM confirms the default workbench, core controls, and outer scroll lock." : "Browser DOM did not satisfy the workbench contract.",
       evidence: [
+        `loginVisible=${login.loginVisible}`,
+        `workbenchHiddenBeforeLogin=${login.workbenchHidden}`,
         `title=${dom.title}`,
         `bodyOverflow=${dom.bodyOverflow}`,
         `htmlOverflow=${dom.htmlOverflow}`,
@@ -3128,6 +3187,7 @@ async function inspectLiveDom(url, options = {}) {
         ...(postGuard ? [`codeAgentPostAttempts=${postGuard.attempts.length}`] : [])
       ],
       observations: {
+        login,
         ...dom,
         ...(postGuard ? { codeAgentPostGuard: postGuard.observation() } : {})
       }
@@ -3161,6 +3221,7 @@ async function inspectLiveHelpRoute(url, options = {}) {
     const page = await browser.newPage({ viewport: { width: 1366, height: 768 } });
     const postGuard = options.noCodeAgentPost ? await installNoCodeAgentPostGuard(page) : null;
     await page.goto(url, { waitUntil: "domcontentloaded", timeout: 12000 });
+    await loginWithDefaultCredentials(page);
     await page.locator('[data-route="help"]').click();
     await page.waitForFunction(() => document.querySelector("#help-content")?.dataset.helpState === "ready", null, { timeout: 8000 });
     const help = await inspectHelpMarkdownRoute(page);
@@ -3217,6 +3278,7 @@ async function inspectLiveGateRoute(url, options = {}) {
     });
     const postGuard = options.noCodeAgentPost ? await installNoCodeAgentPostGuard(page) : null;
     await page.goto(new URL("/gate", url).toString(), { waitUntil: "domcontentloaded", timeout: 12000 });
+    await loginWithDefaultCredentials(page);
     await page.waitForFunction(() => {
       const rows = document.querySelectorAll("#gate-review-body tr");
       const source = document.querySelector("#gate-source-status")?.textContent ?? "";
@@ -3323,6 +3385,395 @@ async function inspectLiveGateRoute(url, options = {}) {
   }
 }
 
+export async function runDevCloudWorkbenchAuthFixtureSmoke() {
+  let chromium;
+  try {
+    ({ chromium } = await importPlaywright());
+  } catch (error) {
+    const summary = `Auth fixture smoke skipped because Playwright is unavailable: ${error.message}`;
+    return {
+      status: "skip",
+      task: "DC-DCSN-P0-2026-003",
+      mode: "auth-fixture-browser",
+      evidenceLevel: "SOURCE",
+      devLive: false,
+      summary,
+      checks: [
+        {
+          id: "auth-browser-dependency",
+          status: "skip",
+          summary: playwrightDependencySummary,
+          evidence: [playwrightDependencyCommand, "package.json dependencies.playwright"]
+        }
+      ],
+      blockers: [
+        {
+          type: "environment_blocker",
+          scope: "auth-browser-dependency",
+          status: "open",
+          summary
+        }
+      ],
+      safety: staticSafety()
+    };
+  }
+
+  const server = await startStaticWebServer({ authFixture: true });
+  let browser;
+  try {
+    browser = await chromium.launch({ headless: true });
+    const desktop = await inspectAuthFixtureViewport(browser, server.url, {
+      width: 1366,
+      height: 768,
+      isMobile: false
+    });
+    const mobile = await inspectAuthFixtureViewport(browser, server.url, {
+      width: 390,
+      height: 844,
+      isMobile: true
+    });
+    const checks = [
+      {
+        id: "auth-login-success-desktop",
+        status: desktop.success.pass ? "pass" : "blocked",
+        viewport: desktop.viewport,
+        summary: "Desktop login accepts admin/hwlab2026 and enters the current Cloud Workbench.",
+        observations: desktop.success
+      },
+      {
+        id: "auth-login-failure-desktop",
+        status: desktop.failure.pass ? "pass" : "blocked",
+        viewport: desktop.viewport,
+        summary: "Desktop login failure stays on the Chinese login page with a bounded error message.",
+        observations: desktop.failure
+      },
+      {
+        id: "auth-refresh-session-desktop",
+        status: desktop.refresh.pass ? "pass" : "blocked",
+        viewport: desktop.viewport,
+        summary: "Desktop refresh preserves the authenticated workbench session.",
+        observations: desktop.refresh
+      },
+      {
+        id: "auth-logout-expiry-desktop",
+        status: desktop.logout.pass && desktop.expired.pass ? "pass" : "blocked",
+        viewport: desktop.viewport,
+        summary: "Desktop logout and expired session both return to the login page.",
+        observations: {
+          logout: desktop.logout,
+          expired: desktop.expired
+        }
+      },
+      {
+        id: "auth-login-success-mobile",
+        status: mobile.success.pass ? "pass" : "blocked",
+        viewport: mobile.viewport,
+        summary: "390x844 mobile login enters the workbench without outer scrolling or hidden controls.",
+        observations: mobile.success
+      },
+      {
+        id: "auth-login-failure-mobile",
+        status: mobile.failure.pass ? "pass" : "blocked",
+        viewport: mobile.viewport,
+        summary: "390x844 mobile login failure keeps the form visible and error text contained.",
+        observations: mobile.failure
+      },
+      {
+        id: "auth-refresh-session-mobile",
+        status: mobile.refresh.pass ? "pass" : "blocked",
+        viewport: mobile.viewport,
+        summary: "390x844 mobile refresh preserves the authenticated session and workbench layout.",
+        observations: mobile.refresh
+      },
+      {
+        id: "auth-logout-expiry-mobile",
+        status: mobile.logout.pass && mobile.expired.pass ? "pass" : "blocked",
+        viewport: mobile.viewport,
+        summary: "390x844 mobile logout and expired session return to login without outer scroll.",
+        observations: {
+          logout: mobile.logout,
+          expired: mobile.expired
+        }
+      }
+    ];
+    const blockers = checks
+      .filter((check) => check.status !== "pass")
+      .map((check) => ({
+        type: "runtime_blocker",
+        scope: check.id,
+        status: "open",
+        summary: check.summary,
+        viewport: check.viewport
+      }));
+    return {
+      status: blockers.length === 0 ? "pass" : "blocked",
+      task: "DC-DCSN-P0-2026-003",
+      mode: "auth-fixture-browser",
+      url: server.url,
+      generatedAt: new Date().toISOString(),
+      evidenceLevel: "SOURCE",
+      devLive: false,
+      summary: "Local browser fixture validates the Cloud Workbench login entry, failure message, session refresh, logout, expiry, and desktop/mobile layout.",
+      refs: ["pikasTech/HWLAB#357", "pikasTech/HWLAB#108"],
+      checks,
+      blockers,
+      safety: {
+        ...staticSafety(),
+        localFixtureOnly: true,
+        hardwareWriteApis: false,
+        codeAgentPostSent: false,
+        statement: "Auth fixture uses local same-origin /auth endpoints only; it does not call hardware write APIs, post Code Agent chat, read Secrets, or deploy DEV."
+      }
+    };
+  } catch (error) {
+    return {
+      status: "blocked",
+      task: "DC-DCSN-P0-2026-003",
+      mode: "auth-fixture-browser",
+      url: server.url,
+      generatedAt: new Date().toISOString(),
+      evidenceLevel: "SOURCE",
+      devLive: false,
+      summary: `Auth fixture smoke failed: ${error.message}`,
+      checks: [],
+      blockers: [
+        {
+          type: "runtime_blocker",
+          scope: "auth-fixture-browser",
+          status: "open",
+          summary: error.message
+        }
+      ],
+      safety: staticSafety()
+    };
+  } finally {
+    if (browser) await browser.close();
+    await server.close();
+  }
+}
+
+async function inspectAuthFixtureViewport(browser, url, viewport) {
+  const context = await browser.newContext({
+    viewport: { width: viewport.width, height: viewport.height },
+    deviceScaleFactor: 1,
+    isMobile: viewport.isMobile === true
+  });
+  try {
+    const failurePage = await context.newPage();
+    await failurePage.goto(url, { waitUntil: "networkidle", timeout: 15000 });
+    const initial = await inspectLoginPage(failurePage);
+    await failurePage.locator("#login-username").fill(defaultAuthCredentials.username);
+    await failurePage.locator("#login-password").fill("wrong-password");
+    await failurePage.locator("#login-submit").click();
+    await failurePage.waitForFunction(() => !document.querySelector("#login-error")?.hidden, null, { timeout: 8000 });
+    const failure = await inspectFailedLoginPage(failurePage, viewport);
+    await failurePage.close();
+
+    const successPage = await context.newPage();
+    await successPage.goto(url, { waitUntil: "networkidle", timeout: 15000 });
+    await loginWithDefaultCredentials(successPage);
+    const success = await inspectAuthenticatedWorkbench(successPage, viewport);
+    await successPage.reload({ waitUntil: "networkidle", timeout: 15000 });
+    const refresh = await inspectAuthenticatedWorkbench(successPage, viewport);
+    await successPage.locator("#logout-button").click();
+    await successPage.waitForFunction(() => document.querySelector("#login-shell")?.hidden === false, null, { timeout: 8000 });
+    const logout = await inspectLoginPage(successPage, viewport);
+    await successPage.close();
+
+    const expiredPage = await context.newPage();
+    await expiredPage.addInitScript(({ username }) => {
+      window.localStorage.setItem("hwlab.cloudWorkbench.auth.v1", JSON.stringify({
+        version: 1,
+        username,
+        issuedAt: Date.now() - 120000,
+        expiresAt: Date.now() - 1000
+      }));
+    }, { username: defaultAuthCredentials.username });
+    await expiredPage.goto(url, { waitUntil: "networkidle", timeout: 15000 });
+    const expired = await inspectLoginPage(expiredPage, viewport);
+    await expiredPage.close();
+
+    return {
+      viewport: { width: viewport.width, height: viewport.height },
+      initial,
+      failure,
+      success,
+      refresh,
+      logout,
+      expired
+    };
+  } finally {
+    await context.close();
+  }
+}
+
+async function loginWithDefaultCredentials(page) {
+  const loginVisible = await page.locator("#login-shell").evaluate((element) => element.hidden === false).catch(() => false);
+  if (!loginVisible) return;
+  await page.locator("#login-username").fill(defaultAuthCredentials.username);
+  await page.locator("#login-password").fill(defaultAuthCredentials.password);
+  await page.locator("#login-submit").click();
+  await page.locator("#command-input").waitFor({ state: "visible", timeout: 12000 });
+}
+
+async function inspectLoginPage(page, viewport = null) {
+  return page.evaluate((viewport) => {
+    const login = document.querySelector("#login-shell");
+    const panel = document.querySelector(".login-panel");
+    const appShell = document.querySelector("[data-app-shell]");
+    const title = document.querySelector("#login-title")?.textContent?.trim() ?? "";
+    const text = login?.textContent?.replace(/\s+/gu, " ").trim() ?? "";
+    const panelBox = panel?.getBoundingClientRect();
+    const inputBoxes = [...document.querySelectorAll(".login-form input, #login-submit")].map((element) => {
+      const box = element.getBoundingClientRect();
+      return {
+        id: element.id,
+        width: box.width,
+        height: box.height,
+        left: box.left,
+        right: box.right,
+        scrollWidth: element.scrollWidth,
+        clientWidth: element.clientWidth
+      };
+    });
+    const forbiddenTerms = ["Gate", "诊断", "验收", "后厨", "BLOCKED", "SOURCE", "DEV-LIVE", "trace", "Secret"];
+    const rootScrollLocked =
+      getComputedStyle(document.documentElement).overflow === "hidden" &&
+      getComputedStyle(document.body).overflow === "hidden" &&
+      document.documentElement.scrollHeight <= document.documentElement.clientHeight + 2 &&
+      document.body.scrollHeight <= document.body.clientHeight + 2;
+    const noHorizontalOverflow =
+      document.documentElement.scrollWidth <= document.documentElement.clientWidth + 2 &&
+      document.body.scrollWidth <= document.body.clientWidth + 2 &&
+      inputBoxes.every((box) => box.scrollWidth <= box.clientWidth + 2);
+    const panelInViewport = Boolean(panelBox) &&
+      panelBox.left >= -1 &&
+      panelBox.right <= window.innerWidth + 1 &&
+      panelBox.top >= -1 &&
+      panelBox.bottom <= window.innerHeight + 1;
+    const copyOk =
+      title === "云工作台登录" &&
+      ["请输入账号和密码。", "用户名", "密码", "登录"].every((term) => text.includes(term)) &&
+      forbiddenTerms.every((term) => !text.includes(term));
+    const loginVisible = Boolean(login && login.hidden === false && panelBox && panelBox.width > 0 && panelBox.height > 0);
+    const workbenchHidden = appShell ? appShell.hidden === true : false;
+    return {
+      viewport: viewport ?? { width: window.innerWidth, height: window.innerHeight },
+      title,
+      textSample: text.slice(0, 180),
+      bodyAuthState: document.body.dataset.authState ?? "",
+      loginVisible,
+      workbenchHidden,
+      copyOk,
+      rootScrollLocked,
+      noHorizontalOverflow,
+      panelInViewport,
+      inputBoxes,
+      pass: loginVisible && workbenchHidden && copyOk && rootScrollLocked && noHorizontalOverflow && panelInViewport
+    };
+  }, viewport);
+}
+
+async function inspectFailedLoginPage(page, viewport) {
+  return page.evaluate((viewport) => {
+    const error = document.querySelector("#login-error");
+    const password = document.querySelector("#login-password");
+    const login = document.querySelector("#login-shell");
+    const appShell = document.querySelector("[data-app-shell]");
+    const errorBox = error?.getBoundingClientRect();
+    const message = error?.textContent?.replace(/\s+/gu, " ").trim() ?? "";
+    const internalLeak = /stack|trace|secret|token|HWLAB_CLOUD|Exception|Error:/iu.test(message);
+    const rootScrollLocked =
+      getComputedStyle(document.documentElement).overflow === "hidden" &&
+      getComputedStyle(document.body).overflow === "hidden" &&
+      document.documentElement.scrollHeight <= document.documentElement.clientHeight + 2 &&
+      document.body.scrollHeight <= document.body.clientHeight + 2;
+    const errorContained = Boolean(errorBox) &&
+      errorBox.width > 0 &&
+      error.scrollWidth <= error.clientWidth + 2 &&
+      errorBox.left >= 0 &&
+      errorBox.right <= window.innerWidth + 1;
+    const pass =
+      login?.hidden === false &&
+      appShell?.hidden === true &&
+      message === "账号或密码不正确，请重新输入。" &&
+      document.activeElement === password &&
+      !internalLeak &&
+      rootScrollLocked &&
+      errorContained;
+    return {
+      viewport,
+      pass,
+      message,
+      internalLeak,
+      passwordFocused: document.activeElement === password,
+      loginVisible: login?.hidden === false,
+      workbenchHidden: appShell?.hidden === true,
+      rootScrollLocked,
+      errorContained
+    };
+  }, viewport);
+}
+
+async function inspectAuthenticatedWorkbench(page, viewport) {
+  await page.locator("#command-input").waitFor({ state: "visible", timeout: 12000 });
+  return page.evaluate((viewport) => {
+    const login = document.querySelector("#login-shell");
+    const appShell = document.querySelector("[data-app-shell]");
+    const visible = (selector) => {
+      const element = document.querySelector(selector);
+      if (!element) return false;
+      const box = element.getBoundingClientRect();
+      const style = getComputedStyle(element);
+      return box.width > 0 && box.height > 0 && style.visibility !== "hidden" && style.display !== "none";
+    };
+    window.scrollTo(0, 240);
+    document.documentElement.scrollTop = 240;
+    document.body.scrollTop = 240;
+    const rootAfterScrollAttempt = {
+      windowScrollY: window.scrollY,
+      htmlScrollTop: document.documentElement.scrollTop,
+      bodyScrollTop: document.body.scrollTop
+    };
+    const rootScrollLocked =
+      getComputedStyle(document.documentElement).overflow === "hidden" &&
+      getComputedStyle(document.body).overflow === "hidden" &&
+      document.documentElement.scrollHeight <= document.documentElement.clientHeight + 2 &&
+      document.body.scrollHeight <= document.body.clientHeight + 2 &&
+      rootAfterScrollAttempt.windowScrollY === 0 &&
+      rootAfterScrollAttempt.htmlScrollTop === 0 &&
+      rootAfterScrollAttempt.bodyScrollTop === 0;
+    const noHorizontalOverflow =
+      document.documentElement.scrollWidth <= document.documentElement.clientWidth + 2 &&
+      document.body.scrollWidth <= document.body.clientWidth + 2;
+    const controlsVisible = {
+      commandInput: visible("#command-input"),
+      commandSend: visible("#command-send"),
+      logout: visible("#logout-button"),
+      hardwareArea: visible(".hardware-status") && visible("[data-hardware-tab='overview']"),
+      m3Control: visible("#m3-control-form")
+    };
+    const pass =
+      login?.hidden === true &&
+      appShell?.hidden === false &&
+      document.body.dataset.authState === "authenticated" &&
+      rootScrollLocked &&
+      noHorizontalOverflow &&
+      Object.values(controlsVisible).every(Boolean);
+    return {
+      viewport,
+      pass,
+      loginHidden: login?.hidden === true,
+      workbenchVisible: appShell?.hidden === false,
+      bodyAuthState: document.body.dataset.authState ?? "",
+      rootScrollLocked,
+      rootAfterScrollAttempt,
+      noHorizontalOverflow,
+      controlsVisible
+    };
+  }, viewport);
+}
+
 async function installNoCodeAgentPostGuard(page) {
   const attempts = [];
   await page.route("**/v1/agent/chat", async (route) => {
@@ -3363,6 +3814,7 @@ async function inspectLiveCodeAgentE2e(url) {
     browser = await chromium.launch({ headless: true });
     const page = await browser.newPage({ viewport: { width: 1366, height: 768 } });
     await page.goto(url, { waitUntil: "domcontentloaded", timeout: 12000 });
+    await loginWithDefaultCredentials(page);
     await page.locator("#command-input").waitFor({ state: "visible", timeout: 12000 });
     const controls = await inspectJourneyControls(page);
     if (!Object.values(controls).every(Boolean)) {
@@ -4003,6 +4455,7 @@ async function runLocalAgentFixtureSmoke({
     });
 
     await page.goto(server.url, { waitUntil: "networkidle", timeout: 15000 });
+    await loginWithDefaultCredentials(page);
     await page.locator("#command-input").waitFor({ state: "visible", timeout: 12000 });
     await page.waitForFunction(
       () => document.querySelector("#live-status")?.textContent?.trim() === "只读模式",
@@ -4217,15 +4670,19 @@ export async function runDevCloudWorkbenchMobileSmoke() {
       isMobile: true
     });
     await page.goto(server.url, { waitUntil: "networkidle", timeout: 15000 });
+    await loginWithDefaultCredentials(page);
     const closed = await inspectMobileWorkbench(page);
     const workspaceScroll = await inspectWorkbenchScrollContract(page, { panelSelector: "#conversation-list" });
     await page.click('[data-route="help"]');
     await page.waitForFunction(() => document.querySelector("#help-content")?.dataset.helpState === "ready", null, { timeout: 8000 });
+    await page.waitForTimeout(150);
     const help = await inspectHelpMarkdownRoute(page);
     await page.goto(new URL("/#/help", server.url).toString(), { waitUntil: "networkidle", timeout: 15000 });
+    await loginWithDefaultCredentials(page);
     await page.waitForFunction(() => document.querySelector("#help-content")?.dataset.helpState === "ready", null, { timeout: 8000 });
     const slashHashHelp = await inspectHelpMarkdownRoute(page);
     await page.goto(new URL("/help", server.url).toString(), { waitUntil: "networkidle", timeout: 15000 });
+    await loginWithDefaultCredentials(page);
     await page.waitForFunction(() => document.querySelector("#help-content")?.dataset.helpState === "ready", null, { timeout: 8000 });
     const directHelp = await inspectHelpMarkdownRoute(page);
     await page.click('[data-route="workspace"]');
@@ -4259,7 +4716,7 @@ export async function runDevCloudWorkbenchMobileSmoke() {
       },
       {
         id: "mobile-help-markdown-route",
-        status: help.nonDefaultMarkdownHelp && help.routeIsHashHelp && help.termsPresent ? "pass" : "blocked",
+        status: help.nonDefaultMarkdownHelp && (help.routeIsHashHelp || help.routeIsSlashHashHelp) && help.termsPresent ? "pass" : "blocked",
         summary: "Help opens from the rail as a non-default hash route rendered from help.md by the vendored Markdown renderer.",
         observations: help
       },
@@ -4492,6 +4949,7 @@ async function inspectQuickPromptsViewport(browser, url, viewport) {
   });
   try {
     await page.goto(url, { waitUntil: "networkidle", timeout: 15000 });
+    await loginWithDefaultCredentials(page);
     await page.locator("#command-input").waitFor({ state: "visible", timeout: 12000 });
     const promptResults = [];
     for (const prompt of codeAgentQuickPromptFixtures) {
@@ -4652,8 +5110,12 @@ async function inspectQuickPromptGeometry(page, viewport) {
 
 async function startStaticWebServer(options = {}) {
   const rootDir = path.resolve(options.rootDir ?? webRoot);
+  const authFixtureSessions = new Set();
   const server = http.createServer(async (request, response) => {
     const url = new URL(request.url ?? "/", "http://127.0.0.1");
+    if (options.authFixture && await handleAuthFixtureApi({ request, response, url, authFixtureSessions })) {
+      return;
+    }
     if (options.m3StatusFixture && await handleM3StatusFixtureApi({ request, response, url, options })) {
       return;
     }
@@ -4693,6 +5155,64 @@ async function startStaticWebServer(options = {}) {
   };
 }
 
+async function handleAuthFixtureApi({ request, response, url, authFixtureSessions }) {
+  if (url.pathname === "/auth/session" && request.method === "GET") {
+    const token = authFixtureCookie(request);
+    jsonResponse(response, 200, token && authFixtureSessions.has(token)
+      ? {
+          authenticated: true,
+          user: { username: defaultAuthCredentials.username },
+          expiresAt: new Date(Date.now() + 60 * 60 * 1000).toISOString()
+        }
+      : { authenticated: false });
+    return true;
+  }
+  if (url.pathname === "/auth/login" && request.method === "POST") {
+    const body = await readJsonBody(request);
+    if (body?.username !== defaultAuthCredentials.username || body?.password !== defaultAuthCredentials.password) {
+      jsonResponse(response, 401, { authenticated: false, error: "invalid_credentials" });
+      return true;
+    }
+    const token = `auth_fixture_${authFixtureSessions.size + 1}`;
+    authFixtureSessions.add(token);
+    const payload = JSON.stringify({
+      authenticated: true,
+      user: { username: defaultAuthCredentials.username },
+      expiresAt: new Date(Date.now() + 60 * 60 * 1000).toISOString()
+    });
+    response.writeHead(200, {
+      "content-type": "application/json; charset=utf-8",
+      "set-cookie": `hwlab_cloud_web_session=${encodeURIComponent(token)}; Path=/; HttpOnly; SameSite=Lax; Max-Age=3600`
+    });
+    response.end(payload);
+    return true;
+  }
+  if (url.pathname === "/auth/logout" && request.method === "POST") {
+    const token = authFixtureCookie(request);
+    if (token) authFixtureSessions.delete(token);
+    response.writeHead(200, {
+      "content-type": "application/json; charset=utf-8",
+      "set-cookie": "hwlab_cloud_web_session=; Path=/; HttpOnly; SameSite=Lax; Max-Age=0"
+    });
+    response.end(JSON.stringify({ authenticated: false }));
+    return true;
+  }
+  if (url.pathname.startsWith("/auth/")) {
+    jsonResponse(response, 404, { authenticated: false, error: "not_found" });
+    return true;
+  }
+  return false;
+}
+
+function authFixtureCookie(request) {
+  const cookie = request.headers.cookie ?? "";
+  for (const part of cookie.split(";")) {
+    const [name, ...value] = part.trim().split("=");
+    if (name === "hwlab_cloud_web_session") return decodeURIComponent(value.join("=") || "");
+  }
+  return "";
+}
+
 async function handleQuickPromptsFixtureApi({ request, response, url }) {
   if (request.method === "GET" && (url.pathname === "/health/live" || url.pathname === "/v1")) {
     jsonResponse(response, 200, {
@@ -5177,6 +5697,7 @@ async function inspectM3StatusFixtureViewport(browser, url, viewport) {
       });
     });
     await page.goto(url, { waitUntil: "domcontentloaded", timeout: 10000 });
+    await loginWithDefaultCredentials(page);
     await page.waitForFunction(() => document.querySelector("#hardware-source-status")?.textContent?.trim() === "实况受阻", null, { timeout: 8000 });
     for (const tab of ["gateways", "box1", "box2", "patch", "overview"]) {
       await page.locator(`[data-hardware-tab="${tab}"]`).click();
@@ -5264,6 +5785,7 @@ async function inspectM3StatusFixtureRefresh(browser, url) {
       });
     });
     await page.goto(url, { waitUntil: "domcontentloaded", timeout: 10000 });
+    await loginWithDefaultCredentials(page);
     await page.waitForFunction(() => document.querySelector("#hardware-source-status")?.textContent?.trim() === "实况受阻", null, { timeout: 8000 });
     await page.locator('[data-hardware-tab="box1"]').click();
     const initialBox1 = await hardwarePanelText(page);
@@ -5537,6 +6059,7 @@ async function inspectWorkbenchLayoutViewport(browser, url, viewport, options =
   const artifacts = { screenshots: [] };
   try {
     await page.goto(url, { waitUntil: "domcontentloaded", timeout: 15000 });
+    await loginWithDefaultCredentials(page);
     await page.locator("#command-input").waitFor({ state: "visible", timeout: 12000 });
     await page.waitForTimeout(150);
     const defaultLayout = await inspectLayoutState(page, {
@@ -5563,6 +6086,7 @@ async function inspectWorkbenchGateLayout(browser, url, viewport, options = {})
   });
   try {
     await page.goto(new URL("/gate", url).toString(), { waitUntil: "domcontentloaded", timeout: 15000 });
+    await loginWithDefaultCredentials(page);
     await page.locator('[data-view="gate"]').waitFor({ state: "visible", timeout: 12000 });
     await page.waitForTimeout(150);
     const currentRoute = await inspectGateLayoutState(page, { viewport, mode: "gate-current" });
@@ -6904,8 +7428,11 @@ async function inspectHelpMarkdownRoute(page) {
       helpContent.scrollTop = 0;
       await new Promise((resolve) => requestAnimationFrame(resolve));
       const before = helpContent.scrollTop;
-      helpContent.scrollTop = helpContent.scrollHeight;
-      await new Promise((resolve) => requestAnimationFrame(resolve));
+      for (let attempt = 0; attempt < 3; attempt += 1) {
+        helpContent.scrollTop = helpContent.scrollHeight;
+        await new Promise((resolve) => requestAnimationFrame(resolve));
+        if (helpContent.scrollTop > before) break;
+      }
       return {
         before,
         after: helpContent.scrollTop,
diff --git a/web/hwlab-cloud-web/app.mjs b/web/hwlab-cloud-web/app.mjs
index 3771f5b5..0a36076d 100644
--- a/web/hwlab-cloud-web/app.mjs
+++ b/web/hwlab-cloud-web/app.mjs
@@ -1,4 +1,5 @@
 import { gateSummary } from "./gate-summary.mjs";
+import { ensureWorkbenchAuth, initWorkbenchLogout } from "./auth.mjs";
 import {
   codeAgentAttributionFromMessage,
   codeAgentFactsFromMessage,
@@ -91,7 +92,9 @@ const viewIds = new Set([...document.querySelectorAll("[data-view]")].map((view)
 let rpcSequence = 0;
 
 const el = {
+  loginShell: byId("login-shell"),
   shell: query("[data-app-shell]"),
+  logoutButton: byId("logout-button"),
   rightSidebarResize: byId("right-sidebar-resize"),
   routePath: byId("route-path"),
   liveStatus: byId("live-status"),
@@ -131,6 +134,11 @@ const el = {
   helpStatus: byId("help-status")
 };
 
+await ensureWorkbenchAuth({
+  loginShell: el.loginShell,
+  appShell: el.shell
+});
+
 const state = {
   conversationId: null,
   sessionId: null,
@@ -165,6 +173,7 @@ initSideTabs();
 initHardwareTabs();
 initQuickActions();
 initCommandBar();
+initWorkbenchLogout(el.logoutButton);
 initM3Control();
 initGateControls();
 renderStaticWorkbench();
@@ -200,7 +209,7 @@ function initRoutes() {
   window.addEventListener("hashchange", () => showView(routeFromLocation()));
   for (const button of document.querySelectorAll("[data-route]")) {
     button.addEventListener("click", () => {
-      window.location.hash = button.dataset.route;
+      window.location.hash = `/${button.dataset.route}`;
     });
   }
   showView(routeFromLocation());
diff --git a/web/hwlab-cloud-web/auth.mjs b/web/hwlab-cloud-web/auth.mjs
new file mode 100644
index 00000000..b99f7f4d
--- /dev/null
+++ b/web/hwlab-cloud-web/auth.mjs
@@ -0,0 +1,339 @@
+const DEFAULT_AUTH_USERNAME = "admin";
+const DEFAULT_AUTH_PASSWORD = "hwlab2026";
+const DEFAULT_SESSION_TTL_MS = 12 * 60 * 60 * 1000;
+const AUTH_STORAGE_KEY = "hwlab.cloudWorkbench.auth.v1";
+const AUTH_ROUTE = Object.freeze({
+  session: "/auth/session",
+  login: "/auth/login",
+  logout: "/auth/logout"
+});
+
+let activeAuth = null;
+let expiryTimer = null;
+
+export async function ensureWorkbenchAuth({ loginShell, appShell }) {
+  if (!loginShell || !appShell) {
+    throw new Error("missing auth shell");
+  }
+
+  const config = resolveAuthConfig();
+  hideWorkbench(appShell);
+  showLogin(loginShell);
+
+  const session = await readActiveSession(config);
+  if (session.authenticated) {
+    return activateAuthenticatedWorkbench({ loginShell, appShell, session, config });
+  }
+
+  return new Promise((resolve) => {
+    initLoginForm({
+      loginShell,
+      appShell,
+      config,
+      onAuthenticated: (authSession) => {
+        resolve(activateAuthenticatedWorkbench({ loginShell, appShell, session: authSession, config }));
+      }
+    });
+  });
+}
+
+export function initWorkbenchLogout(button) {
+  if (!button) return;
+  button.addEventListener("click", async () => {
+    await logoutActiveSession();
+    window.location.reload();
+  });
+}
+
+function resolveAuthConfig() {
+  const configured = globalThis.HWLAB_CLOUD_WEB_CONFIG?.auth ?? {};
+  const sessionTtlMs = clampSessionTtl(configured.sessionTtlMs ?? configured.ttlMs ?? DEFAULT_SESSION_TTL_MS);
+  const mode = ["server", "local", "auto"].includes(configured.mode) ? configured.mode : "auto";
+  return {
+    mode,
+    username: nonEmptyString(configured.username, DEFAULT_AUTH_USERNAME),
+    password: nonEmptyString(configured.password, DEFAULT_AUTH_PASSWORD),
+    sessionTtlMs
+  };
+}
+
+function nonEmptyString(value, fallback) {
+  return typeof value === "string" && value.trim() ? value.trim() : fallback;
+}
+
+function clampSessionTtl(value) {
+  const parsed = Number(value);
+  if (!Number.isFinite(parsed)) return DEFAULT_SESSION_TTL_MS;
+  return Math.min(Math.max(Math.trunc(parsed), 60_000), 7 * 24 * 60 * 60 * 1000);
+}
+
+async function readActiveSession(config) {
+  if (config.mode !== "local") {
+    const serverSession = await fetchServerSession();
+    if (serverSession.available) {
+      return {
+        authenticated: serverSession.authenticated,
+        mode: "server",
+        user: serverSession.user,
+        expiresAt: serverSession.expiresAt
+      };
+    }
+    if (config.mode === "server") {
+      return { authenticated: false, mode: "server" };
+    }
+  }
+
+  return readLocalSession(config);
+}
+
+async function fetchServerSession() {
+  try {
+    const response = await fetch(AUTH_ROUTE.session, {
+      method: "GET",
+      credentials: "same-origin",
+      headers: { accept: "application/json" }
+    });
+    if (response.status === 404 || response.status === 405) {
+      return { available: false };
+    }
+    const payload = await response.json().catch(() => ({}));
+    return {
+      available: true,
+      authenticated: response.ok && payload.authenticated === true,
+      user: safeUser(payload.user),
+      expiresAt: stringOrNull(payload.expiresAt)
+    };
+  } catch {
+    return { available: false };
+  }
+}
+
+function readLocalSession(config) {
+  const now = Date.now();
+  const payload = readStoredLocalSession();
+  if (!payload || payload.expiresAt <= now || payload.username !== config.username) {
+    clearLocalSession();
+    return { authenticated: false, mode: "local" };
+  }
+  return {
+    authenticated: true,
+    mode: "local",
+    user: { username: payload.username },
+    expiresAt: new Date(payload.expiresAt).toISOString()
+  };
+}
+
+function readStoredLocalSession() {
+  try {
+    const raw = window.localStorage?.getItem(AUTH_STORAGE_KEY);
+    if (!raw) return null;
+    const payload = JSON.parse(raw);
+    if (payload?.version !== 1) return null;
+    const expiresAt = Number(payload.expiresAt);
+    if (!Number.isFinite(expiresAt)) return null;
+    return {
+      username: typeof payload.username === "string" ? payload.username : "",
+      expiresAt
+    };
+  } catch {
+    return null;
+  }
+}
+
+function writeLocalSession(config) {
+  const expiresAt = Date.now() + config.sessionTtlMs;
+  try {
+    window.localStorage?.setItem(
+      AUTH_STORAGE_KEY,
+      JSON.stringify({
+        version: 1,
+        username: config.username,
+        issuedAt: Date.now(),
+        expiresAt
+      })
+    );
+  } catch {
+    // A session can still continue for the current page load when storage is unavailable.
+  }
+  return {
+    authenticated: true,
+    mode: "local",
+    user: { username: config.username },
+    expiresAt: new Date(expiresAt).toISOString()
+  };
+}
+
+function clearLocalSession() {
+  try {
+    window.localStorage?.removeItem(AUTH_STORAGE_KEY);
+  } catch {
+    // Ignore storage availability errors.
+  }
+}
+
+function initLoginForm({ loginShell, appShell, config, onAuthenticated }) {
+  const form = required(loginShell, "#login-form");
+  const usernameInput = required(loginShell, "#login-username");
+  const passwordInput = required(loginShell, "#login-password");
+  const submit = required(loginShell, "#login-submit");
+  const error = required(loginShell, "#login-error");
+
+  form.addEventListener("submit", async (event) => {
+    event.preventDefault();
+    setLoginError(error, "");
+    submit.disabled = true;
+    form.setAttribute("aria-busy", "true");
+
+    const username = usernameInput.value.trim();
+    const password = passwordInput.value;
+    const result = await attemptLogin({ username, password, config });
+
+    submit.disabled = false;
+    form.removeAttribute("aria-busy");
+
+    if (!result.authenticated) {
+      hideWorkbench(appShell);
+      showLogin(loginShell);
+      setLoginError(error, "账号或密码不正确，请重新输入。");
+      passwordInput.select();
+      passwordInput.focus();
+      return;
+    }
+
+    onAuthenticated(result);
+  });
+
+  window.requestAnimationFrame(() => usernameInput.focus());
+}
+
+async function attemptLogin({ username, password, config }) {
+  if (config.mode !== "local") {
+    const serverResult = await attemptServerLogin(username, password);
+    if (serverResult.available) {
+      return serverResult.authenticated
+        ? {
+            authenticated: true,
+            mode: "server",
+            user: serverResult.user,
+            expiresAt: serverResult.expiresAt
+          }
+        : { authenticated: false, mode: "server" };
+    }
+    if (config.mode === "server") {
+      return { authenticated: false, mode: "server" };
+    }
+  }
+
+  if (username === config.username && password === config.password) {
+    return writeLocalSession(config);
+  }
+  return { authenticated: false, mode: "local" };
+}
+
+async function attemptServerLogin(username, password) {
+  try {
+    const response = await fetch(AUTH_ROUTE.login, {
+      method: "POST",
+      credentials: "same-origin",
+      headers: {
+        accept: "application/json",
+        "content-type": "application/json"
+      },
+      body: JSON.stringify({ username, password })
+    });
+    if (response.status === 404 || response.status === 405) {
+      return { available: false };
+    }
+    const payload = await response.json().catch(() => ({}));
+    return {
+      available: true,
+      authenticated: response.ok && payload.authenticated === true,
+      user: safeUser(payload.user),
+      expiresAt: stringOrNull(payload.expiresAt)
+    };
+  } catch {
+    return { available: false };
+  }
+}
+
+function activateAuthenticatedWorkbench({ loginShell, appShell, session, config }) {
+  activeAuth = { mode: session.mode, config };
+  hideLogin(loginShell);
+  showWorkbench(appShell);
+  scheduleExpiry(session.expiresAt);
+  return session;
+}
+
+function showLogin(loginShell) {
+  loginShell.hidden = false;
+  loginShell.removeAttribute("aria-hidden");
+  document.body.dataset.authState = "login";
+}
+
+function hideLogin(loginShell) {
+  loginShell.hidden = true;
+  loginShell.setAttribute("aria-hidden", "true");
+}
+
+function showWorkbench(appShell) {
+  appShell.hidden = false;
+  appShell.removeAttribute("aria-hidden");
+  document.body.dataset.authState = "authenticated";
+}
+
+function hideWorkbench(appShell) {
+  appShell.hidden = true;
+  appShell.setAttribute("aria-hidden", "true");
+}
+
+function setLoginError(error, message) {
+  error.textContent = message;
+  error.hidden = !message;
+}
+
+async function logoutActiveSession() {
+  window.clearTimeout(expiryTimer);
+  expiryTimer = null;
+  clearLocalSession();
+  if (activeAuth?.mode === "server") {
+    try {
+      await fetch(AUTH_ROUTE.logout, {
+        method: "POST",
+        credentials: "same-origin",
+        headers: { accept: "application/json" }
+      });
+    } catch {
+      // Reloading after a failed logout still returns to the login check path.
+    }
+  }
+}
+
+function scheduleExpiry(expiresAt) {
+  window.clearTimeout(expiryTimer);
+  expiryTimer = null;
+  const deadline = Date.parse(expiresAt ?? "");
+  if (!Number.isFinite(deadline)) return;
+  const remaining = deadline - Date.now();
+  if (remaining <= 0) {
+    void logoutActiveSession().then(() => window.location.reload());
+    return;
+  }
+  expiryTimer = window.setTimeout(() => {
+    void logoutActiveSession().then(() => window.location.reload());
+  }, Math.min(remaining, 2_147_483_647));
+}
+
+function required(root, selector) {
+  const element = root.querySelector(selector);
+  if (!element) throw new Error(`missing auth element ${selector}`);
+  return element;
+}
+
+function safeUser(user) {
+  const username = typeof user?.username === "string" && user.username.trim() ? user.username.trim() : DEFAULT_AUTH_USERNAME;
+  return { username };
+}
+
+function stringOrNull(value) {
+  return typeof value === "string" && value.trim() ? value.trim() : null;
+}
diff --git a/web/hwlab-cloud-web/index.html b/web/hwlab-cloud-web/index.html
index 344d1e22..b2cd095f 100644
--- a/web/hwlab-cloud-web/index.html
+++ b/web/hwlab-cloud-web/index.html
@@ -7,8 +7,30 @@
     <link rel="stylesheet" href="/styles.css" />
     <script type="module" src="/app.mjs"></script>
   </head>
-  <body>
-    <main class="workbench-shell" data-app-shell data-help-route-policy="non-default-internal-help" data-internal-help-path="/help.md">
+  <body data-auth-state="checking">
+    <section class="login-shell" id="login-shell" data-auth-login aria-labelledby="login-title">
+      <div class="login-panel">
+        <div class="login-heading">
+          <p class="eyebrow">HWLAB</p>
+          <h1 id="login-title">云工作台登录</h1>
+          <p>请输入账号和密码。</p>
+        </div>
+        <form class="login-form" id="login-form" autocomplete="on">
+          <label>
+            <span>用户名</span>
+            <input id="login-username" name="username" type="text" autocomplete="username" inputmode="text" required />
+          </label>
+          <label>
+            <span>密码</span>
+            <input id="login-password" name="password" type="password" autocomplete="current-password" required />
+          </label>
+          <p class="login-error" id="login-error" role="alert" hidden></p>
+          <button class="login-submit" id="login-submit" type="submit">登录</button>
+        </form>
+      </div>
+    </section>
+
+    <main class="workbench-shell" data-app-shell data-help-route-policy="non-default-internal-help" data-internal-help-path="/help.md" hidden aria-hidden="true">
       <aside class="activity-rail" aria-label="工作台活动栏">
         <button class="rail-button active" type="button" data-route="workspace" title="工作台" aria-label="工作台">工作台</button>
         <button class="rail-button" type="button" data-route="gate" title="内部复核" aria-label="内部复核">内部复核</button>
@@ -28,6 +50,7 @@
             <strong id="live-status" class="tone-pending">等待验证</strong>
             <small id="live-detail">正在验证 hwlab-cloud-api /health/live、/v1、/v1/agent/chat 与 /v1/m3/io；未完成前不标为通过。</small>
           </div>
+          <button class="logout-button" id="logout-button" type="button">退出</button>
         </header>
 
         <section class="view workbench-view" id="workspace" data-view="workspace" aria-labelledby="workspace-title">
diff --git a/web/hwlab-cloud-web/scripts/check.mjs b/web/hwlab-cloud-web/scripts/check.mjs
index ddcd4ed0..5c910e6b 100644
--- a/web/hwlab-cloud-web/scripts/check.mjs
+++ b/web/hwlab-cloud-web/scripts/check.mjs
@@ -7,6 +7,7 @@ import {
   runDevCloudWorkbenchLocalAgentFixtureSmoke,
   runDevCloudWorkbenchLayoutSmoke,
   runDevCloudWorkbenchMobileSmoke,
+  runDevCloudWorkbenchAuthFixtureSmoke,
   runDevCloudWorkbenchQuickPromptsFixtureSmoke,
   runDevCloudWorkbenchStaticSmoke
 } from "../../../scripts/src/dev-cloud-workbench-smoke-lib.mjs";
@@ -26,6 +27,7 @@ const repoRoot = path.resolve(rootDir, "../..");
 const requiredFiles = [
   "index.html",
   "styles.css",
+  "auth.mjs",
   "app.mjs",
   "code-agent-facts.mjs",
   "code-agent-status.mjs",
@@ -49,6 +51,7 @@ for (const file of requiredFiles) {
 
 const html = fs.readFileSync(path.resolve(rootDir, "index.html"), "utf8");
 const styles = fs.readFileSync(path.resolve(rootDir, "styles.css"), "utf8");
+const auth = fs.readFileSync(path.resolve(rootDir, "auth.mjs"), "utf8");
 const app = fs.readFileSync(path.resolve(rootDir, "app.mjs"), "utf8");
 const codeAgentFacts = fs.readFileSync(path.resolve(rootDir, "code-agent-facts.mjs"), "utf8");
 const codeAgentStatus = fs.readFileSync(path.resolve(rootDir, "code-agent-status.mjs"), "utf8");
@@ -60,7 +63,7 @@ const buildScript = fs.readFileSync(path.resolve(rootDir, "scripts/build.mjs"),
 const distContractScript = fs.readFileSync(path.resolve(rootDir, "scripts/dist-contract.mjs"), "utf8");
 const markedLicense = fs.readFileSync(path.resolve(rootDir, "third_party/marked/LICENSE"), "utf8");
 const artifactPublisher = fs.readFileSync(path.resolve(repoRoot, "scripts/dev-artifact-publish.mjs"), "utf8");
-const frontendSource = `${html}\n${app}\n${artifactPublisher}`;
+const frontendSource = `${html}\n${auth}\n${app}\n${artifactPublisher}`;
 const requiredTrustedRecordTerms = Object.freeze([
   "Code Agent 对话记录",
   "接线/operation",
@@ -154,6 +157,15 @@ const quickPromptsFillCheck = quickPromptsFixtureSmoke.checks.find((check) => ch
 const quickPromptsNoAutosendCheck = quickPromptsFixtureSmoke.checks.find((check) => check.id === "quick-prompts-write-no-autosend");
 const quickPromptsCopyCheck = quickPromptsFixtureSmoke.checks.find((check) => check.id === "quick-prompts-copy-boundary");
 const quickPromptsLayoutCheck = quickPromptsFixtureSmoke.checks.find((check) => check.id === "quick-prompts-mobile-layout");
+const authFixtureSmoke = await runDevCloudWorkbenchAuthFixtureSmoke();
+const authSuccessDesktopCheck = authFixtureSmoke.checks.find((check) => check.id === "auth-login-success-desktop");
+const authFailureDesktopCheck = authFixtureSmoke.checks.find((check) => check.id === "auth-login-failure-desktop");
+const authRefreshDesktopCheck = authFixtureSmoke.checks.find((check) => check.id === "auth-refresh-session-desktop");
+const authLogoutDesktopCheck = authFixtureSmoke.checks.find((check) => check.id === "auth-logout-expiry-desktop");
+const authSuccessMobileCheck = authFixtureSmoke.checks.find((check) => check.id === "auth-login-success-mobile");
+const authFailureMobileCheck = authFixtureSmoke.checks.find((check) => check.id === "auth-login-failure-mobile");
+const authRefreshMobileCheck = authFixtureSmoke.checks.find((check) => check.id === "auth-refresh-session-mobile");
+const authLogoutMobileCheck = authFixtureSmoke.checks.find((check) => check.id === "auth-logout-expiry-mobile");
 const layoutSmokeReportPath = path.resolve(repoRoot, "tmp/dev-cloud-workbench-layout-web-check.json");
 const layoutSmoke = await runDevCloudWorkbenchLayoutSmoke({ reportPath: layoutSmokeReportPath });
 fs.mkdirSync(path.dirname(layoutSmokeReportPath), { recursive: true });
@@ -213,6 +225,17 @@ assert.equal(quickPromptsFillCheck?.status, "pass", "quick prompt buttons must f
 assert.equal(quickPromptsNoAutosendCheck?.status, "pass", "HWLAB API write quick prompts must not auto-send");
 assert.equal(quickPromptsCopyCheck?.status, "pass", "quick prompt labels must say HWLAB API / Skill CLI without direct hardware-control copy");
 assert.equal(quickPromptsLayoutCheck?.status, "pass", "quick prompt strip must stay contained on desktop and 390x844 mobile");
+assert.equal(authFixtureSmoke.status, "pass", JSON.stringify(authFixtureSmoke.blockers, null, 2));
+assert.equal(authFixtureSmoke.evidenceLevel, "SOURCE");
+assert.equal(authFixtureSmoke.devLive, false);
+assert.equal(authSuccessDesktopCheck?.status, "pass", "desktop login must accept admin/hwlab2026 and enter the Cloud Workbench");
+assert.equal(authFailureDesktopCheck?.status, "pass", "desktop login failure must show a bounded Chinese error and keep workbench hidden");
+assert.equal(authRefreshDesktopCheck?.status, "pass", "desktop refresh must preserve authenticated session state");
+assert.equal(authLogoutDesktopCheck?.status, "pass", "desktop logout and expired session must return to login");
+assert.equal(authSuccessMobileCheck?.status, "pass", "390x844 mobile login must enter workbench without outer scroll or hidden controls");
+assert.equal(authFailureMobileCheck?.status, "pass", "390x844 mobile login failure must keep form visible and error contained");
+assert.equal(authRefreshMobileCheck?.status, "pass", "390x844 mobile refresh must preserve authenticated session state");
+assert.equal(authLogoutMobileCheck?.status, "pass", "390x844 mobile logout and expired session must return to login");
 assert.equal(
   layoutSmoke.status,
   "pass",
diff --git a/web/hwlab-cloud-web/scripts/dist-contract.mjs b/web/hwlab-cloud-web/scripts/dist-contract.mjs
index b11994c3..100bc624 100644
--- a/web/hwlab-cloud-web/scripts/dist-contract.mjs
+++ b/web/hwlab-cloud-web/scripts/dist-contract.mjs
@@ -8,6 +8,7 @@ export const cloudWebDistFreshnessCommand = cloudWebDistBuildCommand;
 export const cloudWebDistRuntimeFiles = Object.freeze([
   "index.html",
   "styles.css",
+  "auth.mjs",
   "app.mjs",
   "code-agent-facts.mjs",
   "code-agent-status.mjs",
diff --git a/web/hwlab-cloud-web/styles.css b/web/hwlab-cloud-web/styles.css
index 7e76398b..4c4a1590 100644
--- a/web/hwlab-cloud-web/styles.css
+++ b/web/hwlab-cloud-web/styles.css
@@ -37,6 +37,7 @@ body {
   width: 100%;
   height: 100%;
   min-height: 0;
+  display: grid;
   overflow: hidden;
   background:
     linear-gradient(90deg, rgba(212, 173, 67, 0.055) 1px, transparent 1px),
@@ -48,12 +49,21 @@ body {
 }
 
 body > [data-app-shell] {
+  grid-area: 1 / 1;
   height: 100%;
   min-height: 0;
   overflow: hidden;
   overscroll-behavior: contain;
 }
 
+body[data-auth-state="login"] {
+  background:
+    linear-gradient(90deg, rgba(212, 173, 67, 0.04) 1px, transparent 1px),
+    linear-gradient(0deg, rgba(111, 183, 169, 0.035) 1px, transparent 1px),
+    var(--bg);
+  background-size: 32px 32px;
+}
+
 button,
 input {
   font: inherit;
@@ -87,6 +97,136 @@ ul {
   background: rgba(15, 17, 16, 0.88);
 }
 
+.workbench-shell[hidden],
+body > [data-app-shell][hidden] {
+  display: none;
+}
+
+.login-shell {
+  grid-area: 1 / 1;
+  width: 100%;
+  height: 100vh;
+  height: 100dvh;
+  min-height: 0;
+  display: grid;
+  place-items: center;
+  padding: 18px;
+  overflow: hidden;
+}
+
+.login-shell[hidden] {
+  display: none;
+}
+
+.login-panel {
+  width: min(100%, 360px);
+  min-width: 0;
+  display: grid;
+  gap: 18px;
+  padding: 24px;
+  background: rgba(24, 27, 24, 0.98);
+  border: 1px solid var(--line-strong);
+  box-shadow: 0 20px 70px rgba(0, 0, 0, 0.34);
+}
+
+.login-heading {
+  display: grid;
+  gap: 6px;
+  min-width: 0;
+}
+
+.login-heading h1 {
+  font-size: 22px;
+}
+
+.login-heading p:last-child {
+  color: var(--muted);
+  font-size: 12px;
+}
+
+.login-form {
+  min-width: 0;
+  display: grid;
+  gap: 12px;
+}
+
+.login-form label {
+  min-width: 0;
+  display: grid;
+  gap: 6px;
+  color: var(--muted);
+  font-size: 11px;
+  font-weight: 760;
+}
+
+.login-form input {
+  width: 100%;
+  min-width: 0;
+  min-height: 42px;
+  padding: 0 11px;
+  border: 1px solid var(--line);
+  background: #101310;
+  color: var(--text);
+  outline: 0;
+}
+
+.login-form input:focus {
+  border-color: var(--accent);
+  box-shadow: inset 3px 0 0 var(--accent);
+}
+
+.login-error {
+  min-height: 22px;
+  padding: 7px 9px;
+  background: rgba(231, 110, 94, 0.1);
+  border: 1px solid rgba(231, 110, 94, 0.52);
+  color: var(--bad);
+  font-size: 12px;
+  line-height: 1.35;
+  overflow-wrap: anywhere;
+}
+
+.login-error[hidden] {
+  display: none;
+}
+
+.login-submit,
+.logout-button {
+  min-width: 0;
+  border: 1px solid var(--line-strong);
+  background: var(--surface-2);
+  color: var(--text);
+  font-weight: 800;
+  cursor: pointer;
+}
+
+.login-submit {
+  min-height: 42px;
+  padding: 0 14px;
+  background: var(--accent);
+  color: #171713;
+}
+
+.login-submit:hover,
+.login-submit:focus-visible,
+.logout-button:hover,
+.logout-button:focus-visible {
+  border-color: var(--accent);
+  outline: 0;
+}
+
+.login-submit:disabled {
+  cursor: wait;
+  opacity: 0.72;
+}
+
+.logout-button {
+  align-self: center;
+  min-height: 34px;
+  padding: 0 12px;
+  font-size: 11px;
+}
+
 .activity-rail,
 .right-sidebar,
 .center-workspace {
@@ -276,7 +416,7 @@ h3 {
 .topbar {
   min-height: 82px;
   display: grid;
-  grid-template-columns: minmax(0, 1fr) minmax(260px, 360px);
+  grid-template-columns: minmax(0, 1fr) minmax(260px, 360px) auto;
   gap: 12px;
   align-items: stretch;
   padding: 12px;
@@ -1711,6 +1851,10 @@ tbody tr:last-child td {
     grid-template-columns: 1fr;
   }
 
+  .logout-button {
+    justify-self: start;
+  }
+
   .hardware-list,
   .m3-control-grid,
   .m3-control-actions {