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/repository/system_config_cache.go

@@ -90,6 +90,7 @@ var (
 	systemConfigListenerOnce   sync.Once
 	systemConfigListenerCtx    context.Context
 	systemConfigListenerCancel context.CancelFunc
+	systemConfigListenerDone   chan struct{}
 )
 
 func ensureSystemConfigCacheListener() {
@@ -102,15 +103,19 @@ func startSystemConfigCacheInvalidationListener() {
 	}
 
 	systemConfigListenerCtx, systemConfigListenerCancel = context.WithCancel(context.Background())
+	systemConfigListenerDone = make(chan struct{})
 
 	go func() {
-		pubsub := db.Redis.Subscribe(systemConfigListenerCtx, SystemConfigBroadcastChannel)
+		listenerCtx := systemConfigListenerCtx
+		defer close(systemConfigListenerDone)
+
+		pubsub := db.Redis.Subscribe(listenerCtx, SystemConfigBroadcastChannel)
 		defer func() {
 			_ = pubsub.Close()
 		}()
 
 		go func() {
-			<-systemConfigListenerCtx.Done()
+			<-listenerCtx.Done()
 			_ = pubsub.Close()
 		}()
 
@@ -135,7 +140,11 @@ func startSystemConfigCacheInvalidationListener() {
 func StopSystemConfigCacheListener() {
 	if systemConfigListenerCancel != nil {
 		systemConfigListenerCancel()
+		if systemConfigListenerDone != nil {
+			<-systemConfigListenerDone
+		}
 		systemConfigListenerCancel = nil
+		systemConfigListenerDone = nil
 	}
 	systemConfigListenerOnce = sync.Once{}
 }