🐛 fix(window): 适配分辨率变化后的窗口边界

- 运行期检测普通窗口是否超出当前可用屏幕并自动收回
- 启动恢复时同步裁剪超过当前屏幕的窗口尺寸

Fixes #594

frontend/src/utils/windowRestoreBounds.test.ts

@@ -23,4 +23,18 @@ describe('windowRestoreBounds', () => {
       { availWidth: 1600, availHeight: 900, availLeft: 0, availTop: 0 },
     )).toEqual({ width: 900, height: 640, x: 350, y: 130 });
   });
+
+  it('shrinks a restored window that is larger than the current visible screen', () => {
+    expect(resolveVisibleStartupWindowBounds(
+      { width: 2560, height: 1440, x: 0, y: 0 },
+      { availWidth: 1440, availHeight: 860, availLeft: 0, availTop: 25 },
+    )).toEqual({ width: 1440, height: 860, x: 0, y: 25 });
+  });
+
+  it('keeps oversized restored bounds inside an offset visible screen', () => {
+    expect(resolveVisibleStartupWindowBounds(
+      { width: 2400, height: 1200, x: 1800, y: 60 },
+      { availWidth: 1728, availHeight: 1040, availLeft: 1728, availTop: 40 },
+    )).toEqual({ width: 1728, height: 1040, x: 1728, y: 40 });
+  });
 });