KYIV, Ukraine (AP) — More than a dozen senior European leaders gathered in Ukraine’s capital on Tuesday to demonstrate solidarity on the fourth anniversary of Russia’s full-scale invasion — a somber landmark in a war that has claimed tens of thousands of lives and heightened fears across Europe about the breadth of Moscow’s ambitions. Ukrainian President Volodymyr Zelenskyy struck a resolute tone despite the immense human and material losses, declaring that Russia has neither “broken