Split diagnostic and lifecycle host contracts

engine/Age.Engine/Hosting/ILifecycleHost.cs

@@ -0,0 +1,20 @@
+namespace Age.Engine.Hosting;
+
+public interface ILifecycleHost
+{
+    // Script context is retained for diagnostics/page location; resource operands are universal packed ids.
+    void EnterScriptContext(string scriptName) { }
+    void ExitScriptContext() { }
+
+    void Sleep(long duration);
+
+    // Native op-0xd5 pacing sleeps inside run-state 0x40 without publishing retained gfx state.
+    // Interactive hosts must keep this distinct from presentation-capable script op-0xc8 sleep.
+    void WaitForTimedCallbackDeadline(long duration) => Sleep(duration);
+
+    void FrameYield();
+
+    // Native op 0x9 resets scene-owned host services before reloading root script resource 0.
+    // Global banks, engine configuration, decoded-asset caches, and persistent profile state survive.
+    void ResetSceneContext() { }
+}