feat: support merging multiple subscriptions

internal/automation/groups.go

@@ -0,0 +1,42 @@
+package automation
+
+import "fmt"
+
+// buildProxyGroups implements the "proxy-groups" ssm feature: for each rule,
+// filter the merged proxy pool by rule.Match and append a new proxy-group
+// containing the matched proxies' display names.
+func buildProxyGroups(finalConfig map[string]interface{}, rules []ProxyGroupRule, proxies []ProxyRef) {
+	for _, rule := range rules {
+		matched := matchProxies(proxies, rule.Match)
+
+		names := make([]interface{}, 0, len(matched))
+		for _, p := range matched {
+			names = append(names, p.DisplayName)
+		}
+		if len(matched) == 0 {
+			fmt.Printf("ℹ️  ssm: proxy-group '%s' matched 0 proxies\n", rule.Name)
+		}
+
+		group := map[string]interface{}{
+			"name":    rule.Name,
+			"type":    defaultString(rule.Type, "select"),
+			"proxies": names,
+		}
+		for k, v := range rule.Extra {
+			group[k] = v
+		}
+		appendProxyGroup(finalConfig, group)
+	}
+}
+
+func defaultString(v, fallback string) string {
+	if v == "" {
+		return fallback
+	}
+	return v
+}
+
+func appendProxyGroup(finalConfig map[string]interface{}, group map[string]interface{}) {
+	existing, _ := finalConfig["proxy-groups"].([]interface{})
+	finalConfig["proxy-groups"] = append(existing, group)
+}