fix(tabs): avoid raising automation window

background/steps/submit-signup-email.js

@@ -185,31 +185,11 @@
       });
     }
 
-    async function normalizeSignupTabWindowForStep2(tabId) {
-      if (
-        !Number.isInteger(tabId)
-        || typeof chrome?.tabs?.get !== 'function'
-        || typeof chrome?.windows?.update !== 'function'
-      ) {
-        return;
-      }
-
-      try {
-        const tab = await chrome.tabs.get(tabId);
-        const windowId = Number(tab?.windowId);
-        if (!Number.isInteger(windowId) || windowId < 0) {
-          return;
-        }
-
-        await chrome.windows.update(windowId, { state: 'normal', focused: true }).catch(() => {});
-        await chrome.windows.update(windowId, {
-          focused: true,
-          width: 1200,
-          height: 900,
-        }).catch(() => {});
-      } catch {
-        // Best-effort only: content-side retries still handle layout recovery.
-      }
+    async function keepSignupTabWindowInBackgroundForStep2(tabId) {
+      // Intentionally no-op: the task tab is locked to the selected Chrome
+      // window by the tab-runtime layer. Step 2 must not focus/raise that
+      // window while the user is working in another app or browser window.
+      void tabId;
     }
 
     async function ensureSignupPhoneEntryReady(tabId) {
@@ -257,7 +237,7 @@
         signupTabId = (await ensureSignupEntryPageReady(2)).tabId;
       } else {
         await chrome.tabs.update(signupTabId, { active: true });
-        await normalizeSignupTabWindowForStep2(signupTabId);
+        await keepSignupTabWindowInBackgroundForStep2(signupTabId);
         await waitForStep2SignupTabToSettle(
           signupTabId,
           '步骤 2：已切换到注册页标签，正在等待页面加载完成并额外稳定 3 秒...'