feat: 新增 grok-4.6 目录、官方定价与请求路径支持

官方目录价：<200k 为 $2 / 缓存读取 $0.50 / $6，≥200k 全部 2 倍。
原先没有独立价卡，/models 宣称可配 reasoning 但请求路径会剥掉 effort。

- 目录与别名接入 grok-4.6 / grok-4.6-latest，默认文本模型仍为 grok-4.5
- 独立回退价卡含缓存读取价与 200k 长上下文倍率
- 保留 reasoning_effort；Chat→Responses 的 cache/vision 桥接同样识别 4.6

backend/internal/handler/gateway_handler.go

@@ -1249,7 +1249,7 @@ func writeGrokModelsList(c *gin.Context, modelIDs []string) {
 
 func grokModelSupportsConfigurableReasoning(modelID string) bool {
 	switch strings.ToLower(strings.TrimSpace(modelID)) {
-	case "grok-4.5", "grok-4.5-latest", "grok", "grok-latest", "grok-build", "grok-build-latest", "grok-build-0.1":
+	case "grok-4.6", "grok-4.6-latest", "grok-4.5", "grok-4.5-latest", "grok", "grok-latest", "grok-build", "grok-build-latest", "grok-build-0.1":
 		return true
 	default:
 		return false

backend/internal/pkg/xai/models.go

@@ -83,6 +83,7 @@ func (o ModelMappingOptions) defaultText() string {
 
 var defaultModels = []Model{
 	// Text
+	{ID: "grok-4.6", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 4.6"},
 	{ID: "grok-4.5", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 4.5"},
 	{ID: "grok-4.3", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 4.3"},
 	{ID: "grok-3-mini", Object: "model", Type: "model", OwnedBy: "xai", DisplayName: "Grok 3 Mini"},
@@ -106,6 +107,8 @@ var defaultModels = []Model{
 var grokTextResponsesModelAliases = map[string]string{
 	"grok":                         DefaultTextModel,
 	"grok-latest":                  DefaultTextModel,
+	"grok-4.6":                     "grok-4.6",
+	"grok-4.6-latest":              "grok-4.6",
 	"grok-4.5":                     DefaultTextModel,
 	"grok-4.5-latest":              DefaultTextModel,
 	"grok-4.3":                     "grok-4.3",

backend/internal/pkg/xai/models_test.go

@@ -52,11 +52,20 @@ func TestCanonicalImagineVideoModel(t *testing.T) {
 func TestIsGrokModelID(t *testing.T) {
 	t.Parallel()
 	require.True(t, IsGrokModelID("grok-4.5"))
+	require.True(t, IsGrokModelID("grok-4.6"))
 	require.True(t, IsGrokModelID("x-ai/grok-4.3"))
 	require.False(t, IsGrokModelID("gpt-5"))
 	require.False(t, IsGrokModelID("claude-sonnet-4"))
 }
 
+func TestDefaultModelsIncludesGrok46(t *testing.T) {
+	t.Parallel()
+	ids := DefaultModelIDs()
+	require.Contains(t, ids, "grok-4.6")
+	require.Equal(t, "grok-4.6", ResolveGrokTextResponsesModelID("grok-4.6"))
+	require.Equal(t, "grok-4.6", ResolveGrokTextResponsesModelID("grok-4.6-latest"))
+}
+
 func TestResolveGrokTextResponsesModelID(t *testing.T) {
 	t.Parallel()
 	require.Equal(t, "grok-4.5", ResolveGrokTextResponsesModelID(""))

backend/internal/pkg/xai/oauth_test.go

@@ -352,6 +352,8 @@ func TestDefaultModelMappingIncludesGrokAliases(t *testing.T) {
 	mapping := DefaultModelMapping()
 	require.Equal(t, "grok-4.5", mapping["grok"])
 	require.Equal(t, "grok-4.5", mapping["grok-latest"])
+	require.Equal(t, "grok-4.6", mapping["grok-4.6"])
+	require.Equal(t, "grok-4.6", mapping["grok-4.6-latest"])
 	require.Equal(t, "grok-4.5", mapping["grok-4.5"])
 	require.Equal(t, "grok-4.5", mapping["grok-4.5-latest"])
 	require.Equal(t, "grok-build-0.1", mapping["grok-build"])

backend/internal/service/billing_service.go

@@ -593,6 +593,19 @@ func (s *BillingService) initFallbackPricing() {
 		SupportsCacheBreakdown: false,
 	}
 
+	// xAI Grok 4.6 (docs.x.ai/developers/models: $2 input / $0.50 cached input /
+	// $6 output per MTok under 200k prompt tokens; ≥200k is 2× on input,
+	// cached input, and output).
+	s.fallbackPrices["grok-4.6"] = &ModelPricing{
+		InputPricePerToken:          2e-6,
+		OutputPricePerToken:         6e-6,
+		CacheReadPricePerToken:      0.5e-6,
+		SupportsCacheBreakdown:      false,
+		LongContextInputThreshold:   200000,
+		LongContextInputMultiplier:  2,
+		LongContextOutputMultiplier: 2,
+	}
+
 	// xAI Grok 4.3 (official docs: $1.25 input / $2.50 output per MTok)
 	s.fallbackPrices["grok-4.3"] = &ModelPricing{
 		InputPricePerToken:         1.25e-6,
@@ -805,6 +818,8 @@ func (s *BillingService) getFallbackPricing(model string) *ModelPricing {
 	switch modelLower {
 	case "grok", "grok-latest", "grok-4.5", "grok-4.5-latest", "grok-build-latest":
 		return s.fallbackPrices["grok-4.5"]
+	case "grok-4.6", "grok-4.6-latest":
+		return s.fallbackPrices["grok-4.6"]
 	case "grok-4.3",
 		"grok-4.20-0309-reasoning",
 		"grok-4.20-0309-non-reasoning",

backend/internal/service/billing_service_test.go

@@ -871,8 +871,8 @@ func TestComputeTokenBreakdown_GptImage2ImageEditIssue4386(t *testing.T) {
 
 	cost := svc.computeTokenBreakdown(pricing, tokens, 1.0, "", false)
 
-	wantTextInput := float64(19) * 5e-6    // 0.000095
-	wantImageInput := float64(352) * 8e-6  // 0.002816
+	wantTextInput := float64(19) * 5e-6     // 0.000095
+	wantImageInput := float64(352) * 8e-6   // 0.002816
 	wantImageOutput := float64(439) * 30e-6 // 0.013170
 	require.InDelta(t, wantTextInput, cost.InputCost, 1e-15, "InputCost 仅含文本输入")
 	require.InDelta(t, wantImageInput, cost.ImageInputCost, 1e-15, "图片输入按 $8/1M 独立计费")
@@ -1166,6 +1166,25 @@ func TestGetModelPricing_Grok45OfficialFallback(t *testing.T) {
 	}
 }
 
+func TestGetModelPricing_Grok46OfficialFallback(t *testing.T) {
+	svc := newTestBillingService()
+
+	for _, model := range []string{"grok-4.6", "grok-4.6-latest"} {
+		model := model
+		t.Run(model, func(t *testing.T) {
+			pricing, err := svc.GetModelPricing(model)
+			require.NoError(t, err)
+			require.InDelta(t, 2e-6, pricing.InputPricePerToken, 1e-12)
+			require.InDelta(t, 6e-6, pricing.OutputPricePerToken, 1e-12)
+			require.InDelta(t, 0.5e-6, pricing.CacheReadPricePerToken, 1e-12)
+			require.Equal(t, 200000, pricing.LongContextInputThreshold)
+			require.InDelta(t, 2.0, pricing.LongContextInputMultiplier, 1e-12)
+			require.InDelta(t, 2.0, pricing.LongContextOutputMultiplier, 1e-12)
+			require.False(t, pricing.SupportsCacheBreakdown)
+		})
+	}
+}
+
 func TestGetModelPricing_GrokCatalogFallbacks(t *testing.T) {
 	svc := newTestBillingService()
 

backend/internal/service/openai_gateway_grok.go

@@ -632,7 +632,8 @@ func normalizeGrokReasoningEffortValue(raw string) (string, bool) {
 func grokSupportsReasoningEffort(model string) bool {
 	model = strings.ToLower(xai.StripGrokProviderPrefix(strings.TrimSpace(model)))
 	switch model {
-	case xai.DefaultTextModel, "grok-4.5-latest", "grok-4.3", "grok-4.3-latest",
+	case xai.DefaultTextModel, "grok-4.5-latest", "grok-4.6", "grok-4.6-latest",
+		"grok-4.3", "grok-4.3-latest",
 		"grok-3-mini", "grok-3-mini-fast", "grok-4.20-0309-reasoning",
 		"grok-4.20-reasoning", "grok-4.20-multi-agent-0309":
 		return true

backend/internal/service/openai_gateway_grok_chat_bridge.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/Wei-Shaw/sub2api/internal/pkg/apicompat"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/xai"
 	"github.com/gin-gonic/gin"
 	"github.com/tidwall/gjson"
 )
@@ -495,8 +496,17 @@ func grokChatResponsesCacheIntentBody(body []byte) ([]byte, error) {
 	return json.Marshal(root)
 }
 
+func grokChatResponsesBridgeModel(model string) bool {
+	switch strings.ToLower(xai.StripGrokProviderPrefix(strings.TrimSpace(model))) {
+	case "grok-4.5", "grok-4.6", "grok-4.6-latest":
+		return true
+	default:
+		return false
+	}
+}
+
 func grokChatResponsesRuntimeEligible(upstreamModel, cacheIdentity string) bool {
-	return strings.TrimSpace(upstreamModel) == "grok-4.5" && strings.TrimSpace(cacheIdentity) != ""
+	return grokChatResponsesBridgeModel(upstreamModel) && strings.TrimSpace(cacheIdentity) != ""
 }
 
 // forwardGrokChatCompletionsViaResponses converts a strictly compatible Chat
@@ -527,7 +537,7 @@ func (s *OpenAIGatewayService) forwardGrokChatCompletionsViaResponses(
 	// for non-composer models, so they would be silently dropped. Route them to
 	// Responses even when no prompt-cache identity is available.
 	hasImageInput := openAIJSONValueMayContainImageInput(gjson.GetBytes(body, "messages"))
-	if !grokChatResponsesRuntimeEligible(upstreamModel, cacheIdentity) && (!hasImageInput || strings.TrimSpace(upstreamModel) != "grok-4.5") {
+	if !grokChatResponsesRuntimeEligible(upstreamModel, cacheIdentity) && (!hasImageInput || !grokChatResponsesBridgeModel(upstreamModel)) {
 		return s.forwardAsRawChatCompletions(ctx, c, account, body, defaultMappedModel)
 	}
 

backend/internal/service/openai_gateway_grok_chat_bridge_test.go

@@ -218,9 +218,12 @@ func TestGrokChatResponsesBridgeEligibility(t *testing.T) {
 func TestGrokChatResponsesRuntimeEligibility(t *testing.T) {
 	t.Parallel()
 	require.True(t, grokChatResponsesRuntimeEligible("grok-4.5", "isolated-id"))
+	require.True(t, grokChatResponsesRuntimeEligible("grok-4.6", "isolated-id"))
+	require.True(t, grokChatResponsesRuntimeEligible("grok-4.6-latest", "isolated-id"))
 	require.False(t, grokChatResponsesRuntimeEligible("grok-4.3", "isolated-id"))
 	require.False(t, grokChatResponsesRuntimeEligible("grok-4.5-build-free", "isolated-id"))
 	require.False(t, grokChatResponsesRuntimeEligible("grok-4.5", ""))
+	require.False(t, grokChatResponsesRuntimeEligible("grok-4.6", ""))
 }
 
 func TestForwardGrokChatViaResponsesNonStreamingCachesAndReturnsChat(t *testing.T) {

backend/internal/service/openai_gateway_grok_test.go

@@ -56,6 +56,8 @@ func TestPatchGrokResponsesBodySanitizesComposerReasoningParameters(t *testing.T
 		{name: "composer legacy alias", upstreamModel: "composer-2.5"},
 		{name: "provider-prefixed composer", upstreamModel: "xai/grok-composer-2.5-fast"},
 		{name: "grok 4.5", upstreamModel: "grok-4.5", wantReasoning: true},
+		{name: "grok 4.6", upstreamModel: "grok-4.6", wantReasoning: true},
+		{name: "grok 4.6 latest", upstreamModel: "grok-4.6-latest", wantReasoning: true},
 	}
 
 	bodyTemplate := []byte(`{

frontend/src/composables/__tests__/useModelWhitelist.spec.ts

@@ -46,6 +46,8 @@ describe('useModelWhitelist', () => {
   it('xAI 模型列表包含 Grok 4.5 官方模型和别名', () => {
     const models = getModelsByPlatform('grok')
 
+    expect(models).toContain('grok-4.6')
+    expect(models).toContain('grok-4.6-latest')
     expect(models).toContain('grok-4.5')
     expect(models).toContain('grok-4.5-latest')
     expect(models).toContain('grok-build-latest')

frontend/src/composables/useModelWhitelist.ts

@@ -136,6 +136,7 @@ const metaModels = [
 
 // xAI Grok
 const xaiModels = [
+  'grok-4.6',
   'grok-4.5',
   'grok-4.3',
   'grok-build-0.1',
@@ -147,6 +148,7 @@ const xaiModels = [
   'grok-4.20-multi-agent-latest',
   'grok-4.3-latest',
   'grok-latest',
+  'grok-4.6-latest',
   'grok-4.5-latest',
   'grok-build-latest',
   'composer-2.5',
@@ -303,6 +305,7 @@ const geminiPresetMappings = [
 ]
 
 const grokPresetMappings = [
+  { label: 'Grok 4.6', from: 'grok-4.6', to: 'grok-4.6', color: 'bg-slate-100 text-slate-700 hover:bg-slate-200 dark:bg-slate-800/50 dark:text-slate-300' },
   { label: 'Grok 4.5', from: 'grok-4.5', to: 'grok-4.5', color: 'bg-slate-100 text-slate-700 hover:bg-slate-200 dark:bg-slate-800/50 dark:text-slate-300' },
   { label: 'Grok 4.3', from: 'grok-4.3', to: 'grok-4.3', color: 'bg-slate-100 text-slate-700 hover:bg-slate-200 dark:bg-slate-800/50 dark:text-slate-300' },
   { label: 'Grok Latest', from: 'grok-latest', to: 'grok-4.5', color: 'bg-emerald-100 text-emerald-700 hover:bg-emerald-200 dark:bg-emerald-900/30 dark:text-emerald-400' },