🔧 chore: Unify subscription plan status toggle with PATCH endpoint

Replace separate enable/disable flows with a single PATCH API that updates the enabled flag.
Update frontend hooks and table actions to call the unified endpoint and keep UI behavior consistent.
Introduce a minimal admin controller handler and route for the status update.

common/str.go

@@ -106,6 +106,16 @@ func GetJsonString(data any) string {
 	return string(b)
 }
 
+// NormalizeBillingPreference clamps the billing preference to valid values.
+func NormalizeBillingPreference(pref string) string {
+	switch strings.TrimSpace(pref) {
+	case "subscription_first", "wallet_first", "subscription_only", "wallet_only":
+		return strings.TrimSpace(pref)
+	default:
+		return "subscription_first"
+	}
+}
+
 // MaskEmail masks a user email to prevent PII leakage in logs
 // Returns "***masked***" if email is empty, otherwise shows only the domain part
 func MaskEmail(email string) string {