feat(audience-sdk): iOS IDFV bridge and device signals (SDK-297, SDK-298)

src/Packages/Audience/Runtime/Plugins/iOS/AudienceMobileBridge.mm

@@ -0,0 +1,15 @@
+#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+
+extern "C" {
+
+const char* _AudienceGetIDFV(void)
+{
+    NSString *idfv = [[UIDevice currentDevice].identifierForVendor UUIDString];
+    // strdup: IL2CPP calls free() on the returned pointer after copying into a
+    // managed string. UTF8String is autoreleased (not malloc'd), so free() would
+    // crash — strdup gives IL2CPP a heap-allocated copy it can safely free.
+    return idfv ? strdup([idfv UTF8String]) : NULL;
+}
+
+}

src/Packages/Audience/Runtime/Unity/DeviceCollector.cs

@@ -3,6 +3,7 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using Immutable.Audience.Unity.Mobile;
 using UnityEngine;
 
 namespace Immutable.Audience.Unity
@@ -45,11 +46,13 @@ internal static Dictionary<string, object> CollectContext()
             return $"{width}x{height}";
         }
 
-        internal static Dictionary<string, object> CollectGameLaunchProperties()
+        internal static Dictionary<string, object> CollectGameLaunchProperties(
+            RuntimePlatform? platformOverride = null)
         {
+            var platform = platformOverride ?? Application.platform;
             var props = new Dictionary<string, object>
             {
-                ["platform"] = Application.platform.ToString(),
+                ["platform"] = PlatformName(platform),
                 ["version"] = Truncate(Application.version, 256),
                 ["buildGuid"] = Truncate(Application.buildGUID, 256),
                 ["unityVersion"] = Truncate(Application.unityVersion, 256),
@@ -66,9 +69,18 @@ internal static Dictionary<string, object> CollectGameLaunchProperties()
             var dpi = (int)Screen.dpi;
             if (dpi > 0) props["screenDpi"] = dpi;
 
-            if (Application.platform == RuntimePlatform.Android)
+            if (platform == RuntimePlatform.Android)
                 props["androidId"] = Truncate(SystemInfo.deviceUniqueIdentifier, 256);
 
+            if (platform == RuntimePlatform.IPhonePlayer)
+            {
+                var idfv = IDFVBridge.GetIDFV();
+                if (idfv != null) props["idfv"] = Truncate(idfv, 256);
+
+                // iOS baseline is 163 DPI (1×); 326 → 2×, 401-460 → 3×.
+                if (dpi > 0) props["screenScale"] = (int)Math.Round(dpi / 163.0);
+            }
+
             return props;
         }
 
@@ -92,6 +104,12 @@ internal static Dictionary<string, object> CollectGameLaunchProperties()
             }
         }
 
+        private static string PlatformName(RuntimePlatform platform) => platform switch
+        {
+            RuntimePlatform.IPhonePlayer => "iOS",
+            _ => platform.ToString(),
+        };
+
         private static string Truncate(string s, int max)
         {
             if (string.IsNullOrEmpty(s) || s.Length <= max) return s;

src/Packages/Audience/Runtime/Unity/Mobile/IDFVBridge.cs

@@ -0,0 +1,26 @@
+#nullable enable
+
+using System;
+#if UNITY_IOS
+using System.Runtime.InteropServices;
+#endif
+
+namespace Immutable.Audience.Unity.Mobile
+{
+    internal static class IDFVBridge
+    {
+        // Replaceable in tests — captures NativeImpl by default.
+        internal static Func<string?> Impl = NativeImpl;
+
+        internal static string? GetIDFV() => Impl();
+
+#if UNITY_IOS
+        [DllImport("__Internal")]
+        private static extern string _AudienceGetIDFV();
+
+        private static string? NativeImpl() => _AudienceGetIDFV();
+#else
+        private static string? NativeImpl() => null;
+#endif
+    }
+}

src/Packages/Audience/Tests/Runtime/Unity/DeviceCollectorTests.cs

@@ -1,8 +1,11 @@
 #nullable enable
 
+using System;
 using System.Collections.Generic;
 using NUnit.Framework;
 using Immutable.Audience.Unity;
+using Immutable.Audience.Unity.Mobile;
+using UnityEngine;
 
 namespace Immutable.Audience.Tests
 {
@@ -89,5 +92,52 @@ public void CollectGameLaunchProperties_ScreenDpi_AbsentWhenZero()
             if (props.TryGetValue("screenDpi", out var dpi))
                 Assert.Greater((int)dpi, 0, "screenDpi must not be 0 when present");
         }
+
+        // -----------------------------------------------------------------
+        // iOS-specific (IDFVBridge + screenScale)
+        // -----------------------------------------------------------------
+
+        private Func<string?>? _originalIDFVImpl;
+
+        [SetUp]
+        public void SetUp() => _originalIDFVImpl = IDFVBridge.Impl;
+
+        [TearDown]
+        public void TearDown() => IDFVBridge.Impl = _originalIDFVImpl!;
+
+        [Test]
+        public void CollectGameLaunchProperties_iOS_IdfvPresentWhenBridgeReturnsValue()
+        {
+            IDFVBridge.Impl = () => "12345678-ABCD-ABCD-ABCD-123456789ABC";
+            var props = DeviceCollector.CollectGameLaunchProperties(RuntimePlatform.IPhonePlayer);
+            Assert.IsTrue(props.ContainsKey("idfv"), "idfv must be present when bridge returns a value");
+            Assert.AreEqual("12345678-ABCD-ABCD-ABCD-123456789ABC", props["idfv"]);
+        }
+
+        [Test]
+        public void CollectGameLaunchProperties_iOS_IdfvAbsentWhenBridgeReturnsNull()
+        {
+            IDFVBridge.Impl = () => null;
+            var props = DeviceCollector.CollectGameLaunchProperties(RuntimePlatform.IPhonePlayer);
+            Assert.IsFalse(props.ContainsKey("idfv"), "idfv must be absent when bridge returns null");
+        }
+
+        [Test]
+        public void CollectGameLaunchProperties_NonIOS_DoesNotContainIdfv()
+        {
+            // IDFVBridge must never be called on non-iOS platforms.
+            IDFVBridge.Impl = () => "should-not-appear";
+            var props = DeviceCollector.CollectGameLaunchProperties();
+            Assert.IsFalse(props.ContainsKey("idfv"),
+                "idfv must not be present on non-iOS platforms");
+        }
+
+        [Test]
+        public void CollectGameLaunchProperties_iOS_ContainsPlatformIPhonePlayer()
+        {
+            IDFVBridge.Impl = () => null;
+            var props = DeviceCollector.CollectGameLaunchProperties(RuntimePlatform.IPhonePlayer);
+            Assert.AreEqual("iOS", props["platform"]);
+        }
     }
 }