diff --git a/docs/design/PLATFORM_HOME_PUBLIC_BROWSE_AND_LOGIN_MODAL_GATING_DESIGN_2026-04-19.md b/docs/design/PLATFORM_HOME_PUBLIC_BROWSE_AND_LOGIN_MODAL_GATING_DESIGN_2026-04-19.md
index 8b1d8574..fd557e2f 100644
--- a/docs/design/PLATFORM_HOME_PUBLIC_BROWSE_AND_LOGIN_MODAL_GATING_DESIGN_2026-04-19.md
+++ b/docs/design/PLATFORM_HOME_PUBLIC_BROWSE_AND_LOGIN_MODAL_GATING_DESIGN_2026-04-19.md
@@ -149,8 +149,15 @@
 
 - 不主动附带 `Authorization`
 - 不因本地 access token 失效去触发 `/api/auth/refresh`
+- 若当前请求本身没有携带 access token，也不允许因为返回 `401` 就额外触发 `/api/auth/refresh`
 - refresh cookie 缺失、refresh 失败、账号状态过期时，不能把首页公开作品广场一起拖成错误态
 
+受保护工作区恢复补充约束：
+
+- 若 URL 或 `sessionStorage` 中残留 `customWorldSessionId`、`customWorldOperationId` 等共创工作区恢复标记，未登录态下不能直接请求对应的 Agent 会话或操作接口
+- 这类“恢复共创工作区”场景要先弹出登录弹窗，登录成功后再恢复原本的工作区或操作上下文
+- 用户未登录且关闭登录弹窗时，前端保持平台页可浏览状态，不允许持续轮询受保护接口
+
 未登录时不读取：
 
 - 自定义世界库
diff --git a/src/components/game-shell/PreGameSelectionFlow.agent.interaction.test.tsx b/src/components/game-shell/PreGameSelectionFlow.agent.interaction.test.tsx
index 46f52405..e6662205 100644
--- a/src/components/game-shell/PreGameSelectionFlow.agent.interaction.test.tsx
+++ b/src/components/game-shell/PreGameSelectionFlow.agent.interaction.test.tsx
@@ -367,7 +367,7 @@ beforeEach(() => {
 test('create tab opens game type modal, keeps AIRP and visual novel locked, and enters agent workspace for RPG', async () => {
   const user = userEvent.setup();
 
-  render(<TestWrapper />);
+  render(<TestWrapper withAuth />);
 
   await clickFirstButtonByName(user, '创作');
   await clickFirstButtonByName(user, /开启新的创作/u);
@@ -456,10 +456,37 @@ test('selecting RPG creation while logged out routes through requireAuth', async
   expect(createCustomWorldAgentSession).not.toHaveBeenCalled();
 });
 
+test('restoring an agent workspace while logged out opens login modal before loading the protected session', async () => {
+  const openLoginModal = vi.fn();
+
+  window.history.replaceState(
+    null,
+    '',
+    '/?customWorldSessionId=custom-world-agent-session-1',
+  );
+
+  render(
+    <TestWrapper
+      authValue={createAuthValue({
+        user: null,
+        openLoginModal,
+        requireAuth: vi.fn(),
+      })}
+    />,
+  );
+
+  await waitFor(() => {
+    expect(openLoginModal).toHaveBeenCalledTimes(1);
+  });
+
+  expect(openLoginModal).toHaveBeenCalledWith(expect.any(Function));
+  expect(getCustomWorldAgentSession).not.toHaveBeenCalled();
+});
+
 test('starting draft generation leaves the agent workspace and shows the generation progress view', async () => {
   const user = userEvent.setup();
 
-  render(<TestWrapper />);
+  render(<TestWrapper withAuth />);
 
   await clickFirstButtonByName(user, '创作');
   await clickFirstButtonByName(user, /开启新的创作/u);
@@ -593,7 +620,7 @@ test('existing draft sessions enter the legacy result layout directly', async ()
     ],
   });
 
-  render(<TestWrapper />);
+  render(<TestWrapper withAuth />);
 
   await clickFirstButtonByName(user, '创作');
   await clickFirstButtonByName(user, /开启新的创作/u);
diff --git a/src/components/game-shell/PreGameSelectionFlow.tsx b/src/components/game-shell/PreGameSelectionFlow.tsx
index 46542469..20c4e21c 100644
--- a/src/components/game-shell/PreGameSelectionFlow.tsx
+++ b/src/components/game-shell/PreGameSelectionFlow.tsx
@@ -186,6 +186,7 @@ export function PreGameSelectionFlow({
   const authUi = useAuthUi();
   const initialAgentUiStateRef = useRef(readCustomWorldAgentUiState());
   const hasAppliedInitialAgentWorkspaceRef = useRef(false);
+  const hasRequestedInitialAgentWorkspaceAuthRef = useRef(false);
   const [generatedCustomWorldProfile, setGeneratedCustomWorldProfile] =
     useState<CustomWorldProfile | null>(null);
   const [savedCustomWorldEntries, setSavedCustomWorldEntries] = useState<
@@ -340,16 +341,29 @@ export function PreGameSelectionFlow({
   );
 
   useEffect(() => {
-    if (hasAppliedInitialAgentWorkspaceRef.current) {
+    const initialAgentSessionId = initialAgentUiStateRef.current.activeSessionId;
+
+    if (!initialAgentSessionId || hasAppliedInitialAgentWorkspaceRef.current) {
+      return;
+    }
+
+    setPlatformTab('create');
+
+    // URL 或 sessionStorage 中残留的共创工作区属于受保护入口，
+    // 未登录时只允许先唤起登录弹窗，不能直接恢复会话请求。
+    if (!authUi?.user) {
+      if (!hasRequestedInitialAgentWorkspaceAuthRef.current) {
+        hasRequestedInitialAgentWorkspaceAuthRef.current = true;
+        authUi?.openLoginModal?.(() => {
+          setSelectionStage('agent-workspace');
+        });
+      }
       return;
     }
 
     hasAppliedInitialAgentWorkspaceRef.current = true;
-    if (initialAgentUiStateRef.current.activeSessionId) {
-      setPlatformTab('create');
-      setSelectionStage('agent-workspace');
-    }
-  }, [setSelectionStage]);
+    setSelectionStage('agent-workspace');
+  }, [authUi?.openLoginModal, authUi?.user, setSelectionStage]);
 
   useEffect(() => {
     if (!selectedDetailEntry) {
@@ -530,6 +544,16 @@ export function PreGameSelectionFlow({
   useEffect(() => {
     if (!activeAgentSessionId) {
       setAgentSession(null);
+      setAgentOperation(null);
+      setIsLoadingAgentSession(false);
+      setStreamingAgentReplyText('');
+      setIsStreamingAgentReply(false);
+      return;
+    }
+
+    if (!authUi?.user) {
+      setAgentSession(null);
+      setAgentOperation(null);
       setIsLoadingAgentSession(false);
       setStreamingAgentReplyText('');
       setIsStreamingAgentReply(false);
@@ -572,13 +596,14 @@ export function PreGameSelectionFlow({
     };
   }, [
     activeAgentSessionId,
+    authUi?.user,
     persistAgentUiState,
     setSelectionStage,
     syncAgentSessionSnapshot,
   ]);
 
   useEffect(() => {
-    if (!activeAgentSessionId || !activeAgentOperationId) {
+    if (!activeAgentSessionId || !activeAgentOperationId || !authUi?.user) {
       return;
     }
 
@@ -638,6 +663,7 @@ export function PreGameSelectionFlow({
   }, [
     activeAgentOperationId,
     activeAgentSessionId,
+    authUi?.user,
     persistAgentUiState,
     syncAgentSessionSnapshot,
   ]);
diff --git a/src/services/apiClient.test.ts b/src/services/apiClient.test.ts
index cfd465bf..4962b9c4 100644
--- a/src/services/apiClient.test.ts
+++ b/src/services/apiClient.test.ts
@@ -157,6 +157,24 @@ describe('apiClient', () => {
     );
   });
 
+  it('does not refresh or emit auth changes for 401 responses without auth context', async () => {
+    fetchMock.mockResolvedValueOnce(createResponseMock({ status: 401 }));
+
+    const response = await fetchWithApiAuth('/api/runtime/protected', {
+      method: 'GET',
+    });
+
+    expect(response.status).toBe(401);
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(fetchMock).toHaveBeenCalledWith(
+      '/api/runtime/protected',
+      expect.objectContaining({
+        credentials: 'same-origin',
+      }),
+    );
+    expect(window.dispatchEvent).not.toHaveBeenCalled();
+  });
+
   it('retries transient get requests before unwrapping the response envelope', async () => {
     fetchMock
       .mockRejectedValueOnce(new TypeError('network unavailable'))
diff --git a/src/services/apiClient.ts b/src/services/apiClient.ts
index e508c46a..1611e567 100644
--- a/src/services/apiClient.ts
+++ b/src/services/apiClient.ts
@@ -351,12 +351,15 @@ export function setStoredAccessToken(
   }
 
   const nextToken = token.trim();
+  const previousToken = getStoredAccessToken();
   if (nextToken) {
     window.localStorage.setItem(ACCESS_TOKEN_KEY, nextToken);
   } else {
     window.localStorage.removeItem(ACCESS_TOKEN_KEY);
   }
-  if (options.emit !== false) {
+
+  // 只有登录态令牌真的发生变化时才广播事件，避免无意义的鉴权重算。
+  if (options.emit !== false && previousToken !== nextToken) {
     emitAuthStateChange();
   }
 }
@@ -370,8 +373,11 @@ export function clearStoredAccessToken(
     return;
   }
 
+  const previousToken = getStoredAccessToken();
   window.localStorage.removeItem(ACCESS_TOKEN_KEY);
-  if (options.emit !== false) {
+
+  // 未登录态下重复清空 token 不应触发状态刷新，否则会放大 401 循环。
+  if (options.emit !== false && previousToken) {
     emitAuthStateChange();
   }
 }
@@ -487,14 +493,20 @@ export async function fetchWithApiAuth(
 
   for (;;) {
     try {
+      const requestHeaders = withAuthorizationHeaders(init.headers, options);
+      const hasAuthHeader = Boolean(
+        requestHeaders.Authorization?.trim() ||
+          requestHeaders.authorization?.trim(),
+      );
       const response = await fetch(input, {
         credentials: 'same-origin',
         ...init,
-        headers: withAuthorizationHeaders(init.headers, options),
+        headers: requestHeaders,
       });
 
       if (
         response.status === 401 &&
+        hasAuthHeader &&
         !options.skipAuth &&
         !options.skipRefresh &&
         !refreshAttempted