feat(providers): add xAI provider with device code OAuth

Add a separate `xai` provider type for xAI Grok CLI subscription accounts.
It is independent of the existing `grok` provider, which reverse-proxies
grok.com with browser cookies; behavior of `grok` is unchanged.

Account binding uses the xAI device code flow, so no local callback
listener is needed and headless deployments can bind accounts. Refresh
tokens can also be imported individually or in batches, and are rotated
on refresh.

OAuth requests default to the cli-chat-proxy Responses API; API keys and
compact stay on api.x.ai. Explicit custom gateways are preserved. Only
`openai:responses` and `openai:responses:compact` are exposed; Chat,
Claude and Gemini clients reach the provider through Aether's existing
cross-format conversion rather than new native endpoints.

Upstream Responses payloads are sanitized for what xAI actually rejects:
`previous_response_id` and `metadata.user_id` are dropped, hosted
`tool_choice` is rewritten, `web_search` is restored for converted
clients, `image_generation` is stripped on older Grok conversation
models, unsupported reasoning effort is removed, and requested
`reasoning.encrypted_content` is preserved with a replay policy keyed on
the configured provider type rather than the model name.

Quota refresh reads /user and /billing?format=credits and stores a
structured usage snapshot; a prepaid balance keeps an account selectable
after the weekly allowance is exhausted. API-key accounts skip the
subscription billing surface. The admin UI shows remaining weekly quota
as a labeled bar in the provider drawer and the pool list.

Co-Authored-By: Claude Opus 5 <[email protected]>

frontend/src/views/admin/PoolManagement.vue

@@ -1700,6 +1700,7 @@ const showAccountQuotaColumn = computed(() => {
     || selectedProviderType.value === 'antigravity'
     || selectedProviderType.value === 'grok'
     || selectedProviderType.value === 'chatgpt_web'
+    || selectedProviderType.value === 'xai'
 })
 
 const desktopColumnWidths = computed(() => {
@@ -2149,6 +2150,7 @@ const quotaRefreshSupported = computed(() => {
     || selectedProviderType.value === 'antigravity'
     || selectedProviderType.value === 'grok'
     || selectedProviderType.value === 'chatgpt_web'
+    || selectedProviderType.value === 'xai'
 })
 
 function canResetCycleStats(_key: PoolKeyDetail): boolean {
@@ -3480,8 +3482,10 @@ function normalizeQuotaLabel(label: string): string {
   if (/spark/i.test(normalized) && normalized.includes('周')) return 'Spark周'
   if (normalized.includes('5H')) return '5H'
   if (normalized.includes('周')) return '周'
+  if (normalized.includes('月')) return '月'
   if (normalized.includes('最低剩余')) return '最低'
   if (normalized === '剩余' || normalized.includes('剩余')) return '剩余'
+  if (normalized === '额度') return '额度'
   return normalized
 }
 
@@ -3490,6 +3494,9 @@ function getQuotaProgressLabel(label: string): string {
   if (label === '5H') return '5H'
   if (label === '周') return '周'
   if (label === '月') return '月'
+  if (label === '周额度') return '周'
+  if (label === '月额度') return '月'
+  if (label === '额度') return '额度'
   if (label === 'Spark5H') return 'Spark5H'
   if (label === 'Spark周') return 'Spark周'
   if (label === '最低') return '最低'
@@ -3498,7 +3505,7 @@ function getQuotaProgressLabel(label: string): string {
 }
 
 function getQuotaProgressCountdown(item: QuotaProgressItem) {
-  const staticResetLabels = ['日', '5H', '周', '月', 'Spark5H', 'Spark周', 'Spark月', 'Auto', 'Fast', 'Expert', 'Heavy', 'Grok 4.3', '生图']
+  const staticResetLabels = ['日', '5H', '周', '月', '周额度', '月额度', '额度', 'Spark5H', 'Spark周', 'Spark月', 'Auto', 'Fast', 'Expert', 'Heavy', 'Grok 4.3', '生图']
   if (!item.allowDynamicReset && !staticResetLabels.includes(item.label)) return null
   if (item.resetAtSeconds == null && item.resetSeconds == null) return null
   return getCodexResetCountdown(
@@ -3567,6 +3574,7 @@ function getQuotaLabelOrder(label: string): number {
   if (label === 'Prompt') return 12
   if (label === 'Flex') return 13
   if (label === '剩余') return 14
+  if (label === '额度') return 14
   if (label === '最低') return 15
   if (label === '生图') return 16
   if (label === '速率') return 17
@@ -3758,7 +3766,7 @@ function buildQuotaProgressItemsFromSnapshot(key: PoolKeyDetail): QuotaProgressI
       .filter((item): item is QuotaProgressItem => item != null)
   }
 
-  if (providerType === 'kiro') {
+  if (providerType === 'kiro' || providerType === 'xai') {
     const quotaResetAtSeconds = getQuotaSnapshotResetAtSeconds(quota)
     const quotaResetSeconds = getQuotaSnapshotResetSeconds(quota)
     const window = getQuotaSnapshotWindow(quota, 'usage')
@@ -3772,12 +3780,13 @@ function buildQuotaProgressItemsFromSnapshot(key: PoolKeyDetail): QuotaProgressI
       : undefined
 
     return [{
-      label: '剩余',
+      label: normalizeQuotaLabel(String(window?.label || '').trim() || '剩余'),
       remainingPercent,
       detail,
       resetAtSeconds: normalizeUnixSeconds(window?.reset_at ?? quotaResetAtSeconds ?? null),
       resetSeconds: normalizeRemainingSeconds(window?.reset_seconds ?? quotaResetSeconds ?? null),
       updatedAtSeconds: getQuotaSnapshotUpdatedAtSeconds(quota),
+      allowDynamicReset: true,
     }]
   }