Update kaigen credit private key

src/Managing.Api/appsettings.Production.json

@@ -36,7 +36,6 @@
   "Kaigen": {
     "BaseUrl": "https://api.kaigen.managing.live",
     "DebitEndpoint": "/api/credits/debit",
-    "RefundEndpoint": "/api/credits/refund",
-    "PrivateKey": "${KAIGEN_PRIVATE_KEY}"
+    "RefundEndpoint": "/api/credits/refund"
   }
 }

src/Managing.Api/appsettings.json

@@ -27,8 +27,7 @@
   "Kaigen": {
     "BaseUrl": "https://api.kaigen.managing.live",
     "DebitEndpoint": "/api/credits/debit",
-    "RefundEndpoint": "/api/credits/refund",
-    "PrivateKey": "0x0fb7fbebde2b9a14b039fa974ad330dd693f91e783cd4ea13ed38be8706835a7"
+    "RefundEndpoint": "/api/credits/refund"
   },
   "N8n": {
     "WebhookUrl": "https://n8n.kai.managing.live/webhook/fa9308b6-983b-42ec-b085-71599d655951"

src/Managing.Infrastructure.Web3/Services/KaigenService.cs

@@ -36,6 +36,14 @@ public class KaigenService : IKaigenService
             PropertyNamingPolicy = JsonNamingPolicy.CamelCase
         };
 
+        // Always read from environment variable for security
+        var envPrivateKey = Environment.GetEnvironmentVariable("KAIGEN_PRIVATE_KEY");
+        if (!string.IsNullOrEmpty(envPrivateKey))
+        {
+            _settings.PrivateKey = envPrivateKey;
+            _logger.LogInformation("Using KAIGEN_PRIVATE_KEY from environment variable");
+        }
+
         // Validate required settings
         if (string.IsNullOrEmpty(_settings.PrivateKey))
         {