merge: 合并 test 分支到 test-dev，解决冲突

解决的冲突文件：
- wire_gen.go: 合并 ConcurrencyService/CRSSyncService 参数和 userAttributeHandler
- gateway_handler.go: 合并 pkg/errors 和 antigravity 导入
- gateway_service.go: 合并 validateUpstreamBaseURL 和 GetAvailableModels
- config.example.yaml: 合并 billing/turnstile 配置和额外 gateway 选项

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/internal/server/middleware/recovery.go

@@ -7,7 +7,7 @@ import (
 	"os"
 	"strings"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
 	"github.com/gin-gonic/gin"
 )

backend/internal/server/middleware/recovery_test.go

@@ -8,7 +8,7 @@ import (
 	"net/http/httptest"
 	"testing"
 
-	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
 	"github.com/gin-gonic/gin"
 	"github.com/stretchr/testify/require"