feat: add grok quota probe parity

frontend/src/i18n/locales/en.ts

@@ -4154,6 +4154,11 @@ export default {
         grokTokens: 'Tok',
         grokUnknown: 'Grok quota is unknown until the first upstream response includes xAI rate-limit headers.',
         grokRetryAfter: 'Retry after {time}',
+        grokProbe: 'Probe',
+        grokProbeTooltip: 'Send a minimal xAI Responses probe and read quota headers',
+        grokResetUnsupported: 'Reset unsupported',
+        grokResetUnsupportedTooltip: 'xAI does not expose reset credits for Grok OAuth accounts',
+        grokNoHeaders: 'No quota headers observed',
         passiveSampled: 'Passive',
         activeQuery: 'Query'
       },

frontend/src/i18n/locales/zh.ts

@@ -3412,6 +3412,11 @@ export default {
         grokTokens: 'Token',
         grokUnknown: 'Grok 配额需等待首次上游响应返回 xAI rate-limit 头后显示。',
         grokRetryAfter: '{time} 后重试',
+        grokProbe: '探测',
+        grokProbeTooltip: '发送最小 xAI Responses 探测请求并读取配额响应头',
+        grokResetUnsupported: '不支持重置',
+        grokResetUnsupportedTooltip: 'xAI 未向 Grok OAuth 账号开放重置额度接口',
+        grokNoHeaders: '未观察到配额响应头',
         passiveSampled: '被动采样',
         activeQuery: '查询'
       },