Tests and package name updated

Runtime/Core/FonepayConfigSO.cs

@@ -0,0 +1,59 @@
+using System;
+using UnityEngine;
+
+namespace Darkmatter.Fonepay
+{
+    // <summary>
+    // ScriptableObject. Holds non-secret config fields serialised to disk. Secret key and password are injected at runtime only — never serialised.
+    // </summary>
+    public class FonepayConfigSO : ScriptableObject
+    {
+        [SerializeField] private FonepayEnvironment environment;
+        [SerializeField] private string merchantCode;
+        [SerializeField] private string username;
+
+        private string _password;
+        private string _secretKey;
+        private bool _credentialsSet;
+
+        // ── public read access ────────────────────────────────────────────
+
+        public FonepayEnvironment Environment => environment;
+        public string MerchantCode => merchantCode;
+        public string Username => username;
+
+        // ── runtime credential injection (called by FonepayPlayModeInjector) ──
+
+        public void SetCredentials(string password, string secretKey)
+        {
+            _password = password;
+            _secretKey = secretKey;
+            _credentialsSet = true;
+        }
+
+        private const string FonepayLiveEndpoint = "https://merchantapi.fonepay.com/api/";
+        private const string FonepayDevEndpoint = "https://dev-merchantapi.fonepay.com/api/";
+
+        // ── used internally by FonepayApiClient and HmacSha512Signer ─────
+
+        internal string GetPassword() => GuardCredentials(_password);
+        internal string GetSecretKey() => GuardCredentials(_secretKey);
+
+        // ── URL resolution ────────────────────────────────────────────────
+
+        public string ResolveBaseUrl() => environment == FonepayEnvironment.Live
+            ? FonepayLiveEndpoint
+            : FonepayDevEndpoint;
+
+        // ── guards ────────────────────────────────────────────────────────
+
+        private string GuardCredentials(string value)
+        {
+            if (!_credentialsSet)
+                throw new FonepayError(0,
+                    "Credentials not set. Call SetCredentials() before using FonepayClient.",
+                    "FonepayConfig.SetCredentials");
+            return value;
+        }
+    }
+}