canonicalheader 8→0 + usestdlibvars 3→0：header key 改为 Go 规范大小写（wire 格式本就如此，纯代码修正）、HTTP 方法常量替代字符串字面量。

Result: {"status":"keep","total_issues":45,"golint_canonicalheader":0,"golint_errname":1,"golint_errorlint":12,"golint_forcetypeassert":3,"golint_gosec":0,"golint_intrange":3,"golint_modernize":5,"golint_nilnil":3,"golint_perfsprint":0,"golint_prealloc":3,"golint_recvcheck":7,"golint_usestdlibvars":0,"golint_wastedassign":7,"golint_total":44,"eslint_problems":1,"eslint_errors":0,"eslint_warnings":1,"tsc_errors":0,"measure_s":38}

internal/router/middlewares.go

@@ -109,7 +109,7 @@ func corsMiddleware() gin.HandlerFunc {
 			c.Writer.Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS, GET, PUT, DELETE, PATCH")
 		}
 
-		if c.Request.Method == "OPTIONS" {
+		if c.Request.Method == http.MethodOptions {
 			c.AbortWithStatus(http.StatusNoContent)
 			return
 		}