feat: add currentPlayer to prompt

tests/core/game-host.test.ts

@@ -410,4 +410,50 @@ describe('GameHost', () => {
             expect(host.status.value).toBe('disposed');
         });
     });
+
+    describe('currentPlayer in prompt', () => {
+        it('should have currentPlayer in PromptEvent', async () => {
+            const { host } = createTestHost();
+
+            const promptPromise = waitForPromptEvent(host);
+            const runPromise = host.commands.run('setup');
+
+            const promptEvent = await promptPromise;
+            expect(promptEvent.currentPlayer).toBe('X');
+            expect(host.activePromptPlayer.value).toBe('X');
+
+            promptEvent.cancel('test cleanup');
+            await runPromise;
+        });
+
+        it('should update activePromptPlayer reactively', async () => {
+            const { host } = createTestHost();
+
+            // Initially null
+            expect(host.activePromptPlayer.value).toBeNull();
+
+            // First prompt - X's turn
+            let promptPromise = waitForPromptEvent(host);
+            let runPromise = host.commands.run('setup');
+            let promptEvent = await promptPromise;
+            expect(promptEvent.currentPlayer).toBe('X');
+            expect(host.activePromptPlayer.value).toBe('X');
+
+            // Make a move
+            promptEvent.tryCommit({ name: 'play', params: ['X', 1, 1], options: {}, flags: {} });
+
+            // Second prompt - O's turn
+            promptPromise = waitForPromptEvent(host);
+            promptEvent = await promptPromise;
+            expect(promptEvent.currentPlayer).toBe('O');
+            expect(host.activePromptPlayer.value).toBe('O');
+
+            // Cancel
+            promptEvent.cancel('test cleanup');
+            await runPromise;
+
+            // After prompt ends, player should be null
+            expect(host.activePromptPlayer.value).toBeNull();
+        });
+    });
 });