fix: ListInstanceGroups 返回 enriched 数据含 instance IDs

- ListInstanceGroups 改用 enrichGroup 返回完整数据
- 包含 readonly_instance_ids/write_instance_ids 供前端穿梭框回显

backend/go.mod

@@ -16,6 +16,7 @@ require (
 	github.com/Azure/go-ntlmssp v0.1.0 // indirect
 	github.com/bytedance/sonic v1.13.2 // indirect
 	github.com/bytedance/sonic/loader v0.2.4 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/cloudwego/base64x v0.1.5 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.8 // indirect
 	github.com/gin-contrib/sse v1.0.0 // indirect
@@ -37,8 +38,10 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pelletier/go-toml/v2 v2.2.3 // indirect
+	github.com/redis/go-redis/v9 v9.19.0 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.12 // indirect
+	go.uber.org/atomic v1.11.0 // indirect
 	golang.org/x/arch v0.15.0 // indirect
 	golang.org/x/net v0.50.0 // indirect
 	golang.org/x/sys v0.41.0 // indirect