fix(android): add explicit JNI activation constructor to OsuGameActivity

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/e7dda39f-3a2e-42c8-b52b-7a8495c6b03a

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>

Author: Copilot

osu.Android/Linker.xml

@@ -102,7 +102,15 @@
        pass (where the .NET Android SDK does include it in the link set), ILLink finds
        the stored rule and preserves the assembly in full.  Removing these entries
        "to silence the warnings" allows ILLink to freely trim JNI-only constructors
-       from AndroidGameActivity, crashing the app on launch. -->
+       from AndroidGameActivity, crashing the app on launch.
+
+       ADDITIONAL DEFENCE (v2026.508.227+): OsuGameActivity now also declares its own
+       explicit (IntPtr, JniHandleOwnership) constructor that chains to base.  Because
+       osu.Android is unambiguously preserve="all" and is always resolvable at
+       descriptor-processing time, this makes the JNI-activation constructor available
+       in the concrete type regardless of whether the IL2007-deferred rule for
+       osu.Framework.Android is honoured.  The v2026.508.226 field crash confirmed
+       that the deferred rule alone is not always sufficient. -->
   <assembly fullname="osu.Framework"         preserve="all" />
   <assembly fullname="osu.Framework.Android" preserve="all" />
   <assembly fullname="ppy.Veldrid.SPIRV"     preserve="all" />

osu.Android/OsuGameActivity.cs

@@ -88,6 +88,19 @@ protected override osu.Framework.Game CreateGame()
             return game;
         }
 
+        // JNI activation constructor. Android's TypeManager.Activate resolves this
+        // constructor via reflection when recreating the managed wrapper from a JNI
+        // handle (e.g. after process restore or across configuration changes). Without
+        // an explicit declaration here the linker might only find the inherited version
+        // in osu.Framework.Android — an assembly that ILLink cannot resolve during
+        // descriptor processing (IL2007), making the preserve="all" rule unreliable for
+        // inherited members. Declaring it in osu.Android (which is unambiguously
+        // preserve="all") guarantees the constructor survives trimming.
+        protected OsuGameActivity(IntPtr handle, JniHandleOwnership transfer)
+            : base(handle, transfer)
+        {
+        }
+
         public OsuGameActivity()
         {
             game = new OsuGameAndroid(this);