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%)

pkg/push/telegram_test.go

@@ -23,7 +23,7 @@ func TestTelegramPusher_Send(t *testing.T) {
 			assert.Equal(t, "application/json", r.Header.Get("Content-Type"))
 
 			err := json.NewDecoder(r.Body).Decode(&receivedReq)
-			require.NoError(t, err)
+			assert.NoError(t, err)
 
 			w.WriteHeader(http.StatusOK)
 			_, _ = w.Write([]byte(`{"ok": true}`))
@@ -55,7 +55,7 @@ func TestTelegramPusher_Send(t *testing.T) {
 		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			var req telegramMessageRequest
 			err := json.NewDecoder(r.Body).Decode(&req)
-			require.NoError(t, err)
+			assert.NoError(t, err)
 			requests = append(requests, &req)
 
 			if len(requests) == 1 {
@@ -84,7 +84,7 @@ func TestTelegramPusher_Send(t *testing.T) {
 
 		require.Len(t, requests, 2)
 		assert.Equal(t, "HTML", requests[0].ParseMode)
-		assert.Equal(t, "", requests[1].ParseMode)
+		assert.Empty(t, requests[1].ParseMode)
 		assert.Contains(t, requests[1].Text, "[INFO] Alert & Info")
 		assert.Contains(t, requests[1].Text, "A < B comparison")
 	})
@@ -96,7 +96,7 @@ func TestTelegramPusher_Send(t *testing.T) {
 			URL:     "https://api.telegram.org",
 		}
 		err := pusher.ValidateConfig(cfg)
-		assert.Error(t, err)
+		require.Error(t, err)
 
 		cfg = Config{
 			Channel: "telegram",
@@ -104,7 +104,7 @@ func TestTelegramPusher_Send(t *testing.T) {
 			Secret:  "token",
 		}
 		err = pusher.ValidateConfig(cfg)
-		assert.Error(t, err)
+		require.Error(t, err)
 
 		cfg = Config{
 			Channel: "telegram",