fix(providers): only block explicit official providers under proxy takeover

The proxy-takeover block previously fell back to the isOfficial heuristic
(empty base_url / missing key) when category was absent. That misjudged
custom providers whose endpoint lives in meta or whose fields are simply
unfilled: their switch button got disabled, making users think the config
was broken. That extra UI block was also "virtual" — the executor in
useProviderActions only ever honored category === "official", so the
front end blocked more than the backend would enforce.

Gate the block solely on explicit category === "official", matching the
executor and unifying both verdicts on a single source of truth.

Also rework the blocked-state UI:
- drop the red "blocked" badge for a plain disabled Enable button
- move title/cursor onto a wrapper span (disabled buttons set
  pointer-events:none, so an on-button title/cursor never fired)
- replace the account-ban warning tooltip with a lighter hint
  (provider.blockedByProxyHint), four locales kept in sync

src/components/providers/ProviderActions.tsx

@@ -7,7 +7,6 @@ import {
   Minus,
   Play,
   Plus,
-  ShieldAlert,
   Terminal,
   TestTube2,
   Trash2,
@@ -45,6 +44,18 @@ interface ProviderActionsProps {
   onSetAsDefault?: () => void;
 }
 
+// 主按钮的呈现状态。title 用于 disabled 态向用户解释为何不可点击；
+// 因 Button 基类带 disabled:pointer-events-none，title 必须挂在外层非禁用
+// 的 wrapper 上才会在 hover 时显示（见下方 <span> 包裹）。
+interface MainButtonState {
+  disabled: boolean;
+  variant: "default" | "secondary";
+  className: string;
+  icon: JSX.Element;
+  text: string;
+  title?: string;
+}
+
 export function ProviderActions({
   appId,
   isCurrent,
@@ -108,7 +119,7 @@ export function ProviderActions({
     }
   };
 
-  const getMainButtonState = () => {
+  const getMainButtonState = (): MainButtonState => {
     if (isOmo) {
       if (isCurrent) {
         return {
@@ -174,16 +185,6 @@ export function ProviderActions({
       };
     }
 
-    if (isOfficialBlockedByProxy) {
-      return {
-        disabled: true,
-        variant: "secondary" as const,
-        className: "opacity-40 cursor-not-allowed",
-        icon: <ShieldAlert className="h-4 w-4" />,
-        text: t("provider.blockedByProxy", { defaultValue: "已拦截" }),
-      };
-    }
-
     if (isCurrent) {
       return {
         disabled: true,
@@ -195,6 +196,17 @@ export function ProviderActions({
       };
     }
 
+    if (isOfficialBlockedByProxy) {
+      return {
+        disabled: true,
+        variant: "default" as const,
+        className: "",
+        icon: <Play className="h-4 w-4" />,
+        text: t("provider.enable"),
+        title: t("provider.blockedByProxyHint"),
+      };
+    }
+
     return {
       disabled: false,
       variant: "default" as const,
@@ -247,16 +259,26 @@ export function ProviderActions({
           );
         })()}
 
-      <Button
-        size="sm"
-        variant={buttonState.variant}
-        onClick={handleMainButtonClick}
-        disabled={buttonState.disabled}
-        className={cn("w-[4.5rem] px-2.5", buttonState.className)}
+      {/* wrapper span 承接 hover：disabled 按钮自身 pointer-events:none，
+          原生 title 与 cursor 都必须挂在未禁用的外层元素上才会生效 */}
+      <span
+        title={buttonState.title}
+        className={cn(
+          "inline-flex",
+          buttonState.disabled && "cursor-not-allowed",
+        )}
       >
-        {buttonState.icon}
-        {buttonState.text}
-      </Button>
+        <Button
+          size="sm"
+          variant={buttonState.variant}
+          onClick={handleMainButtonClick}
+          disabled={buttonState.disabled}
+          className={cn("w-[4.5rem] px-2.5", buttonState.className)}
+        >
+          {buttonState.icon}
+          {buttonState.text}
+        </Button>
+      </span>
 
       <div className="flex items-center gap-1">
         <Button

src/components/providers/ProviderCard.tsx

@@ -199,8 +199,16 @@ export function ProviderCard({
     TEMPLATE_TYPES.OFFICIAL_SUBSCRIPTION;
   const officialSubscriptionEnabled =
     supportsOfficialSubscription && usageEnabled && isOfficialSubscriptionUsage;
+  // 官方判定只认显式 category === "official"（SSOT），不回退 isOfficial 的空字段启发式。
+  // 理由（此判定曾在「纯 category ↔ category+isOfficial 回退」间反复，结论钉死于此）：
+  //  1) 封号保护是高代价决策，不该建立在「base_url/key 缺失」这种脆弱信号上——它无法区分
+  //     「想直连官方」与「自定义但还没填完」，两者都表现为字段为空，必然误伤后者。
+  //  2) 启发式在 UI 多拦的部分，执行层 useProviderActions.ts 也只认 category === "official"、
+  //     并不兑现（绕过 UI 即可切换）→ 属虚保护，却以误伤 category 缺失的自定义供应商为代价。
+  //  3) 预设导入的官方一定带 category="official"，category 缺失的「真官方」现实中≈不存在。
+  // 真官方就该有显式 category；手动新建官方应引导标注，而不是靠空字段猜。
   const isOfficialBlockedByProxy =
-    isProxyTakeover && (provider.category === "official" || isOfficial);
+    isProxyTakeover && provider.category === "official";
   const isCopilot =
     provider.meta?.providerType === PROVIDER_TYPES.GITHUB_COPILOT ||
     provider.meta?.usage_script?.templateType === "github_copilot";

src/i18n/locales/en.json

@@ -109,7 +109,7 @@
     "currentlyUsing": "Currently Using",
     "enable": "Enable",
     "inUse": "In Use",
-    "blockedByProxy": "Blocked",
+    "blockedByProxyHint": "Can't switch to an official provider while proxy takeover is active",
     "editProvider": "Edit Provider",
     "editProviderHint": "Configuration will be applied to the current provider immediately after update.",
     "deleteProvider": "Delete Provider",

src/i18n/locales/ja.json

@@ -109,7 +109,7 @@
     "currentlyUsing": "現在使用中",
     "enable": "有効化",
     "inUse": "使用中",
-    "blockedByProxy": "ブロック",
+    "blockedByProxyHint": "プロキシ引き継ぎモードでは公式プロバイダーに切り替えできません",
     "editProvider": "プロバイダーを編集",
     "editProviderHint": "保存すると現在のプロバイダーにすぐ反映されます。",
     "deleteProvider": "プロバイダーを削除",

src/i18n/locales/zh-TW.json

@@ -109,7 +109,7 @@
     "currentlyUsing": "目前使用",
     "enable": "啟用",
     "inUse": "使用中",
-    "blockedByProxy": "已攔截",
+    "blockedByProxyHint": "代理接管模式下無法切換至官方供應商",
     "editProvider": "編輯供應商",
     "editProviderHint": "更新設定後將立即套用至目前供應商。",
     "deleteProvider": "刪除供應商",

src/i18n/locales/zh.json

@@ -109,7 +109,7 @@
     "currentlyUsing": "当前使用",
     "enable": "启用",
     "inUse": "使用中",
-    "blockedByProxy": "已拦截",
+    "blockedByProxyHint": "代理接管模式下不可切换到官方供应商",
     "editProvider": "编辑供应商",
     "editProviderHint": "更新配置后将立即应用到当前供应商。",
     "deleteProvider": "删除供应商",