Fix credentialed localhost registry resolution to use HTTP

Agent-Logs-Url: https://github.com/j143/basic-docker-engine/sessions/9b259d2d-2dd2-4094-849b-5fb1f50355c2

Co-authored-by: j143 <53068787+j143@users.noreply.github.com>

Author: Copilot

main.go

@@ -617,6 +617,9 @@ func resolveRegistry(imageName string) (string, string) {
 	parts := strings.SplitN(imageName, "/", 2)
 	if len(parts) == 2 {
 		host := parts[0]
+		if at := strings.LastIndex(host, "@"); at >= 0 && at < len(host)-1 {
+			host = host[at+1:]
+		}
 		if strings.Contains(host, ".") || strings.Contains(host, ":") || host == "localhost" {
 			registryURL = registryURLForHost(host)
 			repo = parts[1]

main_test.go

@@ -158,6 +158,12 @@ func TestResolveRegistry(t *testing.T) {
 			wantRegistry:   "http://[::1]:5000/v2/",
 			wantRepository: "alpine:latest",
 		},
+		{
+			name:           "credentialed local registry over http",
+			imageName:      "user:password@localhost:5000/alpine",
+			wantRegistry:   "http://localhost:5000/v2/",
+			wantRepository: "alpine",
+		},
 	}
 
 	for _, tt := range tests {