refactor(chat): remove weekly limit flow

src/app/chat/chat-screen.tsx

@@ -58,19 +58,13 @@ export function ChatScreen() {
     authState.loginStatus !== "notLoggedIn" &&
     authState.loginStatus !== "guest";
 
-  // 消息数量限制由后端统一返回 lockDetail，前端不再处理本地额度。
+  // 发送能力由后端统一返回，当前只处理积分不足引导。
   const showMessageLimitBanner =
     state.upgradePromptVisible &&
-    (state.upgradeReason === "weekly_limit" ||
-      state.upgradeReason === "insufficient_credits");
+    state.upgradeReason === "insufficient_credits";
   const messageLimitTitle =
-    state.upgradeReason === "insufficient_credits"
-      ? "Insufficient credits\nTop up to continue chatting"
-      : "The limit for free chat times\nhas been reached";
-  const messageLimitCtaLabel =
-    state.upgradeReason === "insufficient_credits"
-      ? "Top up credits to continue"
-      : "Unlock your membership to continue";
+    "Insufficient credits\nTop up to continue chatting";
+  const messageLimitCtaLabel = "Top up credits to continue";
 
   const externalBrowserPromptShownRef = useRef(false);
 
@@ -188,15 +182,10 @@ export function ChatScreen() {
   }
 
   function handleMessageLimitUnlock(): void {
-    const subscriptionType =
-      state.upgradeReason === "insufficient_credits"
-        ? getInsufficientCreditsSubscriptionType(userState.isVip)
-        : "vip";
-
     router.push(
       getChatPaywallNavigationUrl(
         authState.loginStatus,
-        subscriptionType,
+        getInsufficientCreditsSubscriptionType(userState.isVip),
       ),
     );
   }

src/app/chat/components/chat-quota-exhausted-banner.tsx

@@ -1,14 +1,14 @@
 "use client";
 /**
- * ChatQuotaExhaustedBanner 游客配额耗尽横幅
+ * ChatQuotaExhaustedBanner 发送受限横幅
  *
  * 何时显示：
- *   - 后端返回 lockDetail.reason="weekly_limit" 且 showUpgrade=true
+ *   - 后端返回 cannotSendReason="insufficient_credits"
  *
  * 视觉规格（与设计稿对齐）：
  *   - 粉→品红渐变背景（与 splash 渐变一致）
- *   - 大字号粉色/白色提示文案（"The limit for free chat times has been reached today"）
- *   - 粉→品红渐变 pill 按钮"Unlock your membership to continue" → 跳 /subscription
+ *   - 大字号粉色/白色提示文案
+ *   - 粉→品红渐变 pill 按钮 → 跳 /subscription
  *
  * 业务关系：
  *   - 与 `src/app/sidebar/components/vip-benefits-card.tsx` 的 "Activate VIP Membership" 行为一致
@@ -36,8 +36,8 @@ export interface ChatQuotaExhaustedBannerProps {
 }
 
 export function ChatQuotaExhaustedBanner({
-  title = "The limit for free chat times\nhas been reached today",
-  ctaLabel = "Unlock your membership to continue",
+  title = "Insufficient credits\nTop up to continue chatting",
+  ctaLabel = "Top up credits to continue",
   onUnlock,
 }: ChatQuotaExhaustedBannerProps) {
   const router = useRouter();