feat: add Grok official subscription quota query

Add SuperGrok subscription usage display, following the existing
Claude Code / Codex official-subscription pattern (protocol ported
from steipete/CodexBar):

- New subscription_grok service: reads Grok CLI credentials from
  ~/.grok/auth.json, calls the grok.com GrokBuildBilling gRPC-web
  endpoint, and parses the response via heuristic protobuf scanning
  (used percent, reset time, zero-usage special case)
- Transient failures (network errors, HTTP 408, gRPC deadline/
  cancelled) propagate as Err so the frontend retries and keeps the
  last good value; auth failures map to Expired with a re-login hint
- Tier naming by reset distance: weekly limit, monthly, or a new
  "credits" tier (i18n added for zh/en/ja/zh-TW; tray shows "c")
- New get_xai_oauth_quota command: xai_oauth providers (managed
  SuperGrok OAuth accounts) query the same billing endpoint with
  their bound account token; ProviderCard auto-renders the quota
  footer for them and hides the usage-script entry, and the tray /
  usage-script path routes xai_oauth providers to the managed
  account instead of the host app's CLI credentials
- UsageScriptModal: drop the config-content heuristic for official
  detection; category === "official" is the single source of truth

Claude-Session: https://claude.ai/code/session_01LSNvhEfuoJHaQLZcYQgBU5

src-tauri/src/commands/provider.rs

@@ -3,6 +3,7 @@ use tauri::{Emitter, Manager, State};
 
 use crate::app_config::AppType;
 use crate::commands::copilot::CopilotAuthState;
+use crate::commands::xai_oauth::XaiOAuthState;
 use crate::error::AppError;
 use crate::provider::{ClaudeDesktopMode, Provider};
 use crate::services::{
@@ -442,6 +443,7 @@ pub async fn queryProviderUsage(
     app_handle: tauri::AppHandle,
     state: State<'_, AppState>,
     copilot_state: State<'_, CopilotAuthState>,
+    xai_state: State<'_, XaiOAuthState>,
     #[allow(non_snake_case)] providerId: String, // 使用 camelCase 匹配前端
     app: String,
 ) -> Result<crate::provider::UsageResult, String> {
@@ -454,8 +456,14 @@ pub async fn queryProviderUsage(
     //      不写失败快照、不 emit：保留上一份托盘快照，与前端 react-query reject
     //      保留上次 data 的语义一致；否则失败快照会经 useUsageCacheBridge 盲写
     //      回 query 缓存，抹掉 reject 本该保留的旧值。
-    let inner =
-        query_provider_usage_inner(&state, &copilot_state, app_type.clone(), &providerId).await;
+    let inner = query_provider_usage_inner(
+        &state,
+        &copilot_state,
+        &xai_state,
+        app_type.clone(),
+        &providerId,
+    )
+    .await;
     if let Ok(snapshot) = &inner {
         let payload = serde_json::json!({
             "kind": "script",
@@ -521,6 +529,7 @@ fn resolve_coding_plan_credentials(
 async fn query_provider_usage_inner(
     state: &AppState,
     copilot_state: &CopilotAuthState,
+    xai_state: &XaiOAuthState,
     app_type: AppType,
     provider_id: &str,
 ) -> Result<crate::provider::UsageResult, String> {
@@ -689,9 +698,19 @@ async fn query_provider_usage_inner(
             });
         }
 
-        let quota = crate::services::subscription::get_subscription_quota(app_type.as_str())
-            .await
-            .map_err(|e| format!("Failed to query subscription quota: {e}"))?;
+        // xAI OAuth 托管供应商的额度属绑定的 SuperGrok 账号，而非所在 app 的
+        // CLI 凭据（对 codex/claude 而言 CLI 凭据是 ChatGPT/Claude 订阅，跨了
+        // 订阅体系，查出来的数字张冠李戴）。
+        let quota = if provider.map(Provider::is_xai_oauth).unwrap_or(false) {
+            let account_id = provider
+                .and_then(|p| p.meta.as_ref())
+                .and_then(|m| m.managed_account_id_for("xai_oauth"));
+            crate::commands::xai_oauth::query_xai_oauth_quota_for(xai_state, account_id).await?
+        } else {
+            crate::services::subscription::get_subscription_quota(app_type.as_str())
+                .await
+                .map_err(|e| format!("Failed to query subscription quota: {e}"))?
+        };
 
         if !quota.success {
             return Ok(crate::provider::UsageResult {

src-tauri/src/commands/xai_oauth.rs

@@ -3,6 +3,7 @@
 use crate::proxy::providers::xai_oauth_auth::XaiOAuthManager;
 use crate::proxy::providers::XAI_API_BASE_URL;
 use crate::services::model_fetch::FetchedModel;
+use crate::services::subscription::{CredentialStatus, SubscriptionQuota};
 use serde::Deserialize;
 use std::sync::Arc;
 use std::time::Duration;
@@ -11,6 +12,68 @@ use tokio::sync::RwLock;
 
 pub struct XaiOAuthState(pub Arc<RwLock<XaiOAuthManager>>);
 
+/// 查询 xAI OAuth (SuperGrok 反代) 订阅额度的共享核心
+///
+/// 与 `get_codex_oauth_quota` 平行：数据走 cc-switch 自管的 xAI OAuth token，
+/// 而非 Grok CLI 的 ~/.grok/auth.json。两者是同一个 OAuth client
+/// （client_id 与 Grok CLI 一致），token 对 grok.com 账单端点等效，因此
+/// 复用 `subscription_grok::query_grok_quota`，协议与 Grok CLI 路径完全一致。
+///
+/// 供两处调用：`get_xai_oauth_quota` 命令（前端 footer）与
+/// `commands::provider` 的 official_subscription 分支（用量脚本/托盘路径，
+/// xai_oauth 供应商的额度属绑定的 SuperGrok 账号而非所在 app 的 CLI 凭据）。
+///
+/// - `account_id` 未指定时回退到 `XaiOAuthManager` 的默认账号
+/// - 没有任何账号时返回 `not_found`，前端 `SubscriptionQuotaView` 会静默不渲染
+/// - 瞬时传输失败以 `Err` 传播（前端 reject → retry + 保留上次成功值）
+pub(crate) async fn query_xai_oauth_quota_for(
+    state: &XaiOAuthState,
+    account_id: Option<String>,
+) -> Result<SubscriptionQuota, String> {
+    let manager = state.0.read().await;
+
+    // 解析最终使用的账号 ID：显式 > 默认账号 > 无账号 (not_found)
+    let resolved = match account_id
+        .as_deref()
+        .map(str::trim)
+        .filter(|id| !id.is_empty())
+    {
+        Some(id) => Some(id.to_string()),
+        None => manager.default_account_id().await,
+    };
+    let Some(id) = resolved else {
+        return Ok(SubscriptionQuota::not_found("xai_oauth"));
+    };
+
+    // 获取（必要时自动刷新）access_token
+    let token = match manager.get_valid_token_for_account(&id).await {
+        Ok(t) => t,
+        Err(e) => {
+            return Ok(SubscriptionQuota::error(
+                "xai_oauth",
+                CredentialStatus::Expired,
+                format!("xAI OAuth token unavailable: {e}"),
+            ));
+        }
+    };
+
+    crate::services::subscription_grok::query_grok_quota(
+        &token,
+        "xai_oauth",
+        "Please re-login via cc-switch.",
+    )
+    .await
+}
+
+/// 查询 xAI OAuth (SuperGrok 反代) 订阅额度
+#[tauri::command(rename_all = "camelCase")]
+pub async fn get_xai_oauth_quota(
+    account_id: Option<String>,
+    state: State<'_, XaiOAuthState>,
+) -> Result<SubscriptionQuota, String> {
+    query_xai_oauth_quota_for(&state, account_id).await
+}
+
 #[derive(Debug, Deserialize)]
 struct ModelsResponse {
     #[serde(default)]