fix(antigravity): support upstream accounts and custom model_mapping in scheduling

- GetAccessToken: add upstream branch to read api_key from credentials
- shouldTriggerAntigravitySmartRetry: relax check from IsOAuth to Platform-based
- isModelSupportedByAccount/WithContext: replace IsAntigravityModelSupported
  whitelist with mapAntigravityModel for unified scheduling/forwarding logic
- mapAntigravityModel: fix edge case where wildcard target equals request model
- Update tests for new behavior and add custom model_mapping test cases

backend/internal/service/antigravity_gateway_service.go

@@ -600,11 +600,12 @@ func mapAntigravityModel(account *Account, requestedModel string) string {
 		return mapped
 	}
 
-	// 如果 mapped == requestedModel，检查是否在映射表 key 中显式配置
+	// 如果 mapped == requestedModel，检查是否在映射表中配置（精确或通配符）
 	// 这区分两种情况：
 	// 1. 映射表中有 "model-a": "model-a"（显式透传）→ 返回 model-a
-	// 2. 映射表中没有 model-a 的配置 → 返回空（不支持）
-	if _, exists := mapping[requestedModel]; exists {
+	// 2. 通配符匹配 "claude-*": "claude-sonnet-4-5" 恰好目标等于请求名 → 返回 model-a
+	// 3. 映射表中没有 model-a 的配置 → 返回空（不支持）
+	if account.IsModelSupported(requestedModel) {
 		return requestedModel
 	}
 
@@ -2042,7 +2043,7 @@ func parseAntigravitySmartRetryInfo(body []byte) *antigravitySmartRetryInfo {
 //   - waitDuration: 等待时间（智能重试时使用，shouldRateLimitModel=true 时为 0）
 //   - modelName: 限流的模型名称
 func shouldTriggerAntigravitySmartRetry(account *Account, respBody []byte) (shouldRetry bool, shouldRateLimitModel bool, waitDuration time.Duration, modelName string) {
-	if !account.IsOAuth() {
+	if account.Platform != PlatformAntigravity {
 		return false, false, 0, ""
 	}
 

backend/internal/service/antigravity_rate_limit_test.go

@@ -524,8 +524,8 @@ func TestParseAntigravitySmartRetryInfo(t *testing.T) {
 }
 
 func TestShouldTriggerAntigravitySmartRetry(t *testing.T) {
-	oauthAccount := &Account{Type: AccountTypeOAuth}
-	setupTokenAccount := &Account{Type: AccountTypeSetupToken}
+	oauthAccount := &Account{Type: AccountTypeOAuth, Platform: PlatformAntigravity}
+	setupTokenAccount := &Account{Type: AccountTypeSetupToken, Platform: PlatformAntigravity}
 	apiKeyAccount := &Account{Type: AccountTypeAPIKey}
 
 	tests := []struct {

backend/internal/service/antigravity_smart_retry_test.go

@@ -343,13 +343,13 @@ func TestHandleSmartRetry_503_ModelCapacityExhausted_ReturnsSwitchError(t *testi
 	require.Equal(t, "gemini-3-pro-high", repo.modelRateLimitCalls[0].modelKey)
 }
 
-// TestHandleSmartRetry_NonOAuthAccount_ContinuesDefaultLogic 测试非 OAuth 账号走默认逻辑
-func TestHandleSmartRetry_NonOAuthAccount_ContinuesDefaultLogic(t *testing.T) {
+// TestHandleSmartRetry_NonAntigravityAccount_ContinuesDefaultLogic 测试非 Antigravity 平台账号走默认逻辑
+func TestHandleSmartRetry_NonAntigravityAccount_ContinuesDefaultLogic(t *testing.T) {
 	account := &Account{
 		ID:       4,
 		Name:     "acc-4",
-		Type:     AccountTypeAPIKey, // 非 OAuth 账号
-		Platform: PlatformAntigravity,
+		Type:     AccountTypeAPIKey, // 非 Antigravity 平台账号
+		Platform: PlatformAnthropic,
 	}
 
 	// 即使是模型限流响应，非 OAuth 账号也应该走默认逻辑
@@ -385,7 +385,7 @@ func TestHandleSmartRetry_NonOAuthAccount_ContinuesDefaultLogic(t *testing.T) {
 	result := handleSmartRetry(params, resp, respBody, "https://ag-1.test", 0, availableURLs)
 
 	require.NotNil(t, result)
-	require.Equal(t, smartRetryActionContinue, result.action, "non-OAuth account should continue default logic")
+	require.Equal(t, smartRetryActionContinue, result.action, "non-Antigravity platform account should continue default logic")
 	require.Nil(t, result.resp)
 	require.Nil(t, result.err)
 	require.Nil(t, result.switchError)

backend/internal/service/antigravity_token_provider.go

@@ -42,7 +42,18 @@ func (p *AntigravityTokenProvider) GetAccessToken(ctx context.Context, account *
 	if account == nil {
 		return "", errors.New("account is nil")
 	}
-	if account.Platform != PlatformAntigravity || account.Type != AccountTypeOAuth {
+	if account.Platform != PlatformAntigravity {
+		return "", errors.New("not an antigravity account")
+	}
+	// upstream 类型：直接从 credentials 读取 api_key，不走 OAuth 刷新流程
+	if account.Type == AccountTypeUpstream {
+		apiKey := account.GetCredential("api_key")
+		if apiKey == "" {
+			return "", errors.New("upstream account missing api_key in credentials")
+		}
+		return apiKey, nil
+	}
+	if account.Type != AccountTypeOAuth {
 		return "", errors.New("not an antigravity oauth account")
 	}
 

backend/internal/service/gateway_service.go

@@ -2587,6 +2587,9 @@ func (s *GatewayService) isModelSupportedByAccountWithContext(ctx context.Contex
 		// 应用 thinking 后缀后检查最终模型是否在账号映射中
 		if enabled, ok := ctx.Value(ctxkey.ThinkingEnabled).(bool); ok {
 			finalModel := applyThinkingModelSuffix(mapped, enabled)
+			if finalModel == mapped {
+				return true // thinking 后缀未改变模型名，映射已通过
+			}
 			return account.IsModelSupported(finalModel)
 		}
 		return true

backend/internal/service/gateway_service_antigravity_whitelist_test.go

@@ -80,21 +80,21 @@ func TestGatewayService_isModelSupportedByAccountWithContext_ThinkingMode(t *tes
 		thinkingEnabled bool
 		expected        bool
 	}{
-		// 场景 1: 配置 claude-sonnet-4-5-thinking，请求 claude-sonnet-4-5 + thinking=true
-		// 最终模型名 = claude-sonnet-4-5-thinking，应该匹配
+		// 场景 1: 只配置 claude-sonnet-4-5-thinking，请求 claude-sonnet-4-5 + thinking=true
+		// mapAntigravityModel 找不到 claude-sonnet-4-5 的映射 → 返回 false
 		{
-			name: "thinking_enabled_matches_thinking_model",
+			name: "thinking_enabled_no_base_mapping_returns_false",
 			modelMapping: map[string]any{
 				"claude-sonnet-4-5-thinking": "claude-sonnet-4-5-thinking",
 			},
 			requestedModel:  "claude-sonnet-4-5",
 			thinkingEnabled: true,
-			expected:        true,
+			expected:        false,
 		},
 		// 场景 2: 只配置 claude-sonnet-4-5-thinking，请求 claude-sonnet-4-5 + thinking=false
-		// 最终模型名 = claude-sonnet-4-5，不在 mapping 中，应该不匹配
+		// mapAntigravityModel 找不到 claude-sonnet-4-5 的映射 → 返回 false
 		{
-			name: "thinking_disabled_no_match_thinking_only_mapping",
+			name: "thinking_disabled_no_base_mapping_returns_false",
 			modelMapping: map[string]any{
 				"claude-sonnet-4-5-thinking": "claude-sonnet-4-5-thinking",
 			},
@@ -145,15 +145,16 @@ func TestGatewayService_isModelSupportedByAccountWithContext_ThinkingMode(t *tes
 			thinkingEnabled: true,
 			expected:        true, // claude-sonnet-4-5-thinking 匹配 claude-*
 		},
-		// 场景 7: 其他模型（非 sonnet-4-5）的 thinking 不受影响
+		// 场景 7: 只配置 thinking 变体但没有基础模型映射 → 返回 false
+		// mapAntigravityModel 找不到 claude-opus-4-6 的映射
 		{
-			name: "opus_thinking_unchanged",
+			name: "opus_thinking_no_base_mapping_returns_false",
 			modelMapping: map[string]any{
 				"claude-opus-4-6-thinking": "claude-opus-4-6-thinking",
 			},
 			requestedModel:  "claude-opus-4-6",
 			thinkingEnabled: true,
-			expected:        true, // claude-opus-4-6 映射到 claude-opus-4-6-thinking，匹配
+			expected:        false,
 		},
 	}
 
@@ -175,3 +176,65 @@ func TestGatewayService_isModelSupportedByAccountWithContext_ThinkingMode(t *tes
 		})
 	}
 }
+
+// TestGatewayService_isModelSupportedByAccount_CustomMappingNotInDefault 测试自定义模型映射中
+// 不在 DefaultAntigravityModelMapping 中的模型能通过调度
+func TestGatewayService_isModelSupportedByAccount_CustomMappingNotInDefault(t *testing.T) {
+	svc := &GatewayService{}
+
+	// 自定义映射中包含不在默认映射中的模型
+	account := &Account{
+		Platform: PlatformAntigravity,
+		Credentials: map[string]any{
+			"model_mapping": map[string]any{
+				"my-custom-model":   "actual-upstream-model",
+				"gpt-4o":            "some-upstream-model",
+				"llama-3-70b":       "llama-3-70b-upstream",
+				"claude-sonnet-4-5": "claude-sonnet-4-5",
+			},
+		},
+	}
+
+	// 自定义模型应该通过（不在 DefaultAntigravityModelMapping 中也可以）
+	require.True(t, svc.isModelSupportedByAccount(account, "my-custom-model"))
+	require.True(t, svc.isModelSupportedByAccount(account, "gpt-4o"))
+	require.True(t, svc.isModelSupportedByAccount(account, "llama-3-70b"))
+	require.True(t, svc.isModelSupportedByAccount(account, "claude-sonnet-4-5"))
+
+	// 不在自定义映射中的模型不通过
+	require.False(t, svc.isModelSupportedByAccount(account, "gpt-3.5-turbo"))
+	require.False(t, svc.isModelSupportedByAccount(account, "unknown-model"))
+
+	// 空模型允许
+	require.True(t, svc.isModelSupportedByAccount(account, ""))
+}
+
+// TestGatewayService_isModelSupportedByAccountWithContext_CustomMappingThinking
+// 测试自定义映射 + thinking 模式的交互
+func TestGatewayService_isModelSupportedByAccountWithContext_CustomMappingThinking(t *testing.T) {
+	svc := &GatewayService{}
+
+	// 自定义映射同时配置基础模型和 thinking 变体
+	account := &Account{
+		Platform: PlatformAntigravity,
+		Credentials: map[string]any{
+			"model_mapping": map[string]any{
+				"claude-sonnet-4-5":          "claude-sonnet-4-5",
+				"claude-sonnet-4-5-thinking": "claude-sonnet-4-5-thinking",
+				"my-custom-model":            "upstream-model",
+			},
+		},
+	}
+
+	// thinking=true: claude-sonnet-4-5 → mapped=claude-sonnet-4-5 → +thinking → check IsModelSupported(claude-sonnet-4-5-thinking)=true
+	ctx := context.WithValue(context.Background(), ctxkey.ThinkingEnabled, true)
+	require.True(t, svc.isModelSupportedByAccountWithContext(ctx, account, "claude-sonnet-4-5"))
+
+	// thinking=false: claude-sonnet-4-5 → mapped=claude-sonnet-4-5 → check IsModelSupported(claude-sonnet-4-5)=true
+	ctx = context.WithValue(context.Background(), ctxkey.ThinkingEnabled, false)
+	require.True(t, svc.isModelSupportedByAccountWithContext(ctx, account, "claude-sonnet-4-5"))
+
+	// 自定义模型（非 claude）不受 thinking 后缀影响，mapped 成功即通过
+	ctx = context.WithValue(context.Background(), ctxkey.ThinkingEnabled, true)
+	require.True(t, svc.isModelSupportedByAccountWithContext(ctx, account, "my-custom-model"))
+}