feat(diagnostic): 阶段 0A 输入链路被动探测与线程归属复现

tests/UiFixture.cpp

@@ -1,5 +1,6 @@
 #include "StellarX.h"
 
+#include <array>
 #include <filesystem>
 #include <fstream>
 #include <memory>
@@ -88,6 +89,25 @@ int main(int argc, char** argv)
 		button->setTooltipText("stationary tip");
 		window.addControl(std::move(button));
 	}
+	else if (scenario == "input-probe")
+	{
+		// 该场景只提供一个可聚焦的 EasyX 顶层窗口，不让控件消费或改写键盘/IME 消息。
+		const std::array<std::string, 5> instructions{
+			"StellarX input probe - manual IME run",
+			"1. Click this window, then switch to the requested IME.",
+			"2. Type only the agreed non-sensitive test strings.",
+			"3. Cover commit, candidate select, cancel and language switch.",
+			"4. Close the window after the checklist is complete."
+		};
+		int y = 30;
+		for (const std::string& line : instructions)
+		{
+			auto label = std::make_unique<Label>(20, y, line, WHITE, Background);
+			label->setTextdisap(true);
+			window.addControl(std::move(label));
+			y += 42;
+		}
+	}
 	else if (scenario == "native-close")
 	{
 		// 只创建顶层窗口，由 UI 驱动发送原生关闭命令并验证宿主循环自行退出。