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/zone/legacy_import.go

@@ -103,7 +103,7 @@ func ImportLegacyTx(ctx context.Context, tx *sql.Tx, postgres bool) (report Impo
 		`), domain).Scan(&existingID, &existingZoneDomain)
 		if scanErr == nil {
 			if existingZoneDomain != root {
-				report.Conflicts = append(report.Conflicts, fmt.Sprintf("%s: global domain conflict", domain))
+				report.Conflicts = append(report.Conflicts, domain+": global domain conflict")
 			} else if item.ProxyRouteID != nil {
 				if _, bindErr := tx.ExecContext(ctx, q(`
 					UPDATE of_zone_domains
@@ -147,7 +147,7 @@ func ImportLegacyTx(ctx context.Context, tx *sql.Tx, postgres bool) (report Impo
 	}
 
 	if len(report.Conflicts) > 0 {
-		return report, fmt.Errorf("legacy data has conflicts")
+		return report, errors.New("legacy data has conflicts")
 	}
 	return report, nil
 }
@@ -292,7 +292,7 @@ func rebindSQL(query string, postgres bool) string {
 	var b strings.Builder
 	b.Grow(len(query) + len(query)/4)
 	n := 0
-	for i := 0; i < len(query); i++ {
+	for i := range len(query) {
 		if query[i] == '?' {
 			n++
 			b.WriteByte('$')

internal/apps/openflare/zone/stats.go

@@ -183,10 +183,7 @@ func emptyStatsSeries(since, until time.Time, bucketMinutes int) []StatsPoint {
 	}
 	// Cap points to keep chart readable.
 	maxPoints := 120
-	capacity := int(end.Sub(start)/bucket) + 1
-	if capacity > maxPoints {
-		capacity = maxPoints
-	}
+	capacity := min(int(end.Sub(start)/bucket)+1, maxPoints)
 	points := make([]StatsPoint, 0, capacity)
 	for cursor := start; !cursor.After(end) && len(points) < maxPoints; cursor = cursor.Add(bucket) {
 		points = append(points, StatsPoint{BucketStartedAt: cursor})