后端与全仓代码质量清理（golangci 扩展集 · 测试质量 · 并发安全 · 文档同步）

代码质量全量清理，零行为变化：golangci 扩展集 13 类 linter（gosec/modernize/perfsprint/canonicalheader/usestdlibvars/wastedassign/intrange/errorlint/forcetypeassert/recvcheck/exhaustive/unparam）全量修复，测试代码质量（testifylint/thelper/usetesting）25→0，frpc 进程生命周期真 bug（进程组击杀）、全仓 go test -race 6 类数据竞争（含 1 个生产竞争）、SPDX license 头补齐 131 文件、前端测试套件 next-intl 迁移后 44 失败→全绿、过期 swagger 文档重新生成、pnpm-workspace 构建审批。

Experiments: #2-#17, #18, #20, #21, #23
Metric: total_issues 108 → 8 (-92.6%)

internal/apps/openflare/config_version/helpers.go

@@ -6,6 +6,7 @@ package config_version
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net"
 	"strconv"
@@ -27,7 +28,7 @@ func normalizeSnapshotDomains(domains []string) ([]string, error) {
 	for _, raw := range domains {
 		domain := strings.ToLower(strings.TrimSpace(raw))
 		if domain == "" || strings.Contains(domain, "://") || strings.Contains(domain, "/") {
-			return nil, fmt.Errorf("domains payload is invalid")
+			return nil, errors.New("domains payload is invalid")
 		}
 		if _, ok := seen[domain]; ok {
 			continue
@@ -36,7 +37,7 @@ func normalizeSnapshotDomains(domains []string) ([]string, error) {
 		normalized = append(normalized, domain)
 	}
 	if len(normalized) == 0 {
-		return nil, fmt.Errorf("domain is required")
+		return nil, errors.New("domain is required")
 	}
 	return normalized, nil
 }
@@ -55,7 +56,7 @@ func decodeStoredUpstreams(raw string, fallbackOriginURL string) ([]string, erro
 	}
 	var upstreams []string
 	if err := json.Unmarshal([]byte(text), &upstreams); err != nil {
-		return nil, fmt.Errorf("upstreams payload is invalid")
+		return nil, errors.New("upstreams payload is invalid")
 	}
 	return normalizeUpstreams(fallbackOriginURL, upstreams)
 }
@@ -79,7 +80,7 @@ func normalizeUpstreams(originURL string, upstreams []string) ([]string, error)
 		normalized = append(normalized, value)
 	}
 	if len(normalized) == 0 {
-		return nil, fmt.Errorf("upstream is required")
+		return nil, errors.New("upstream is required")
 	}
 	return normalized, nil
 }
@@ -91,7 +92,7 @@ func decodeStoredCustomHeaders(raw string) ([]customHeaderInput, error) {
 	}
 	var headers []customHeaderInput
 	if err := json.Unmarshal([]byte(text), &headers); err != nil {
-		return nil, fmt.Errorf("custom_headers payload is invalid")
+		return nil, errors.New("custom_headers payload is invalid")
 	}
 	return headers, nil
 }
@@ -103,7 +104,7 @@ func decodeStoredCacheRules(raw string) ([]string, error) {
 	}
 	var rules []string
 	if err := json.Unmarshal([]byte(text), &rules); err != nil {
-		return nil, fmt.Errorf("cache_rules payload is invalid")
+		return nil, errors.New("cache_rules payload is invalid")
 	}
 	normalized := make([]string, 0, len(rules))
 	for _, rule := range rules {