refactor(app): tighten chat and sync boundaries

src/app/chat/chat-screen.tsx

@@ -7,18 +7,12 @@ import { useRouter } from "next/navigation";
 import { useAuthState } from "@/stores/auth/auth-context";
 import { useChatDispatch, useChatState } from "@/stores/chat/chat-context";
 import { useUserState } from "@/stores/user/user-context";
-import { ROUTE_BUILDERS, ROUTES } from "@/router/routes";
+import { ROUTES } from "@/router/routes";
 import {
   openChatInExternalBrowser,
   recordExternalBrowserPromptShown,
   resolveExternalBrowserPromptEligibility,
 } from "@/lib/chat/chat_external_browser";
-import {
-  consumePendingChatUnlock,
-  peekPendingChatUnlock,
-  savePendingChatUnlock,
-  type PendingChatUnlockKind,
-} from "@/lib/navigation/chat_unlock_session";
 
 import { MobileShell } from "@/app/_components/core";
 
@@ -27,7 +21,7 @@ import {
   ChatArea,
   ChatHeader,
   ChatInputBar,
-  ChatQuotaExhaustedBanner,
+  ChatInsufficientCreditsBanner,
   ExternalBrowserDialog,
   HistoryUnlockDialog,
   InsufficientCreditsDialog,
@@ -40,6 +34,7 @@ import {
   isChatDevelopmentEnvironment,
   shouldStartExternalBrowserPrompt,
 } from "./chat-screen.helpers";
+import { useChatUnlockNavigationFlow } from "./hooks/use-chat-unlock-navigation-flow";
 import styles from "./components/chat-screen.module.css";
 
 export function ChatScreen() {
@@ -50,13 +45,15 @@ export function ChatScreen() {
   const router = useRouter();
   const [showExternalBrowserDialog, setShowExternalBrowserDialog] =
     useState(false);
-  const unlockPaywallRequest = state.unlockPaywallRequest;
+  const {
+    unlockPaywallRequest,
+    requestMessageUnlock,
+    closeInsufficientCreditsDialog,
+    confirmInsufficientCreditsDialog,
+  } = useChatUnlockNavigationFlow({ returnUrl: ROUTES.chat });
 
   // isGuest 派生（chat-screen 是唯一知道这个值的地方 —— chat 机器无 isGuest 字段）
   const isGuest = deriveIsGuest(authState.loginStatus);
-  const isAuthenticatedUser =
-    authState.loginStatus !== "notLoggedIn" &&
-    authState.loginStatus !== "guest";
 
   // 发送能力由后端统一返回，当前只处理积分不足引导。
   const showMessageLimitBanner =
@@ -108,75 +105,11 @@ export function ChatScreen() {
     authState.loginStatus,
   ]);
 
-  useEffect(() => {
-    if (!state.historyLoaded || !isAuthenticatedUser) return;
-
-    const pending = peekPendingChatUnlock();
-    if (!pending || pending.returnUrl !== ROUTES.chat) return;
-
-    const consumed = consumePendingChatUnlock();
-    if (!consumed) return;
-
-    chatDispatch({
-      type: "ChatUnlockMessageRequested",
-      messageId: consumed.messageId,
-      kind: consumed.kind,
-    });
-  }, [
-    chatDispatch,
-    isAuthenticatedUser,
-    state.historyLoaded,
-  ]);
-
-  function handleCloseInsufficientCreditsDialog(): void {
-    chatDispatch({ type: "ChatUnlockPaywallNavigationConsumed" });
-  }
-
-  function handleConfirmInsufficientCreditsDialog(): void {
-    if (!unlockPaywallRequest) return;
-
-    savePendingChatUnlock({
-      messageId: unlockPaywallRequest.messageId,
-      kind: unlockPaywallRequest.kind,
-      returnUrl: ROUTES.chat,
-      stage: "payment",
-    });
-    chatDispatch({ type: "ChatUnlockPaywallNavigationConsumed" });
-    router.push(
-      ROUTE_BUILDERS.subscription(
-        getInsufficientCreditsSubscriptionType(userState.isVip),
-        { returnTo: "chat" },
-      ),
-    );
-  }
-
   async function handleOpenExternalBrowser(): Promise<void> {
     setShowExternalBrowserDialog(false);
     await openChatInExternalBrowser();
   }
 
-  function requestMessageUnlock(
-    messageId: string,
-    kind: PendingChatUnlockKind,
-  ): void {
-    if (!isAuthenticatedUser) {
-      savePendingChatUnlock({
-        messageId,
-        kind,
-        returnUrl: ROUTES.chat,
-        stage: "auth",
-      });
-      router.push(ROUTE_BUILDERS.authWithRedirect(ROUTES.chat));
-      return;
-    }
-
-    chatDispatch({
-      type: "ChatUnlockMessageRequested",
-      messageId,
-      kind,
-    });
-  }
-
   function handleUnlockPrivateMessage(messageId: string): void {
     requestMessageUnlock(messageId, "private");
   }
@@ -222,7 +155,7 @@ export function ChatScreen() {
           />
 
           {showMessageLimitBanner ? (
-            <ChatQuotaExhaustedBanner
+            <ChatInsufficientCreditsBanner
               title={messageLimitTitle}
               ctaLabel={messageLimitCtaLabel}
               onUnlock={handleMessageLimitUnlock}
@@ -258,8 +191,8 @@ export function ChatScreen() {
           creditBalance={unlockPaywallRequest?.creditBalance ?? 0}
           requiredCredits={unlockPaywallRequest?.requiredCredits ?? 0}
           shortfallCredits={unlockPaywallRequest?.shortfallCredits ?? 0}
-          onClose={handleCloseInsufficientCreditsDialog}
-          onConfirm={handleConfirmInsufficientCreditsDialog}
+          onClose={closeInsufficientCreditsDialog}
+          onConfirm={confirmInsufficientCreditsDialog}
         />
       </div>
     </MobileShell>