feat(滚动): 添加分类切换时重置虚拟滚动位置功能

添加 scrollKey 属性到 AppGrid 组件，当分类变化时自动重置滚动位置
添加相关单元测试验证滚动重置功能

src/__tests__/unit/AppGrid.test.ts

@@ -0,0 +1,101 @@
+import { render } from "@testing-library/vue";
+import { defineComponent, h, nextTick } from "vue";
+import { describe, expect, it, vi } from "vitest";
+
+import AppGrid from "@/components/AppGrid.vue";
+import type { App } from "@/global/typedefinition";
+
+vi.mock("@/components/AppCard.vue", () => ({
+  default: defineComponent({
+    name: "AppCard",
+    props: {
+      app: {
+        type: Object,
+        required: true,
+      },
+    },
+    setup(props) {
+      return () => h("div", props.app.name);
+    },
+  }),
+}));
+
+vi.mock("vue-virtual-scroller", () => ({
+  RecycleScroller: defineComponent({
+    name: "RecycleScroller",
+    props: {
+      items: {
+        type: Array,
+        required: true,
+      },
+    },
+    setup(props, { attrs, slots }) {
+      return () =>
+        h(
+          "div",
+          {
+            ...attrs,
+            style: "max-height: 320px; overflow-y: auto;",
+          },
+          (props.items as Array<{ id: number; apps: App[] }>).map((item) =>
+            slots.default?.({ item }),
+          ),
+        );
+    },
+  }),
+}));
+
+const createApp = (index: number, category: string): App => ({
+  name: `App ${index}`,
+  pkgname: `app-${category}-${index}`,
+  version: "1.0.0",
+  filename: "app.deb",
+  torrent_address: "",
+  author: "",
+  contributor: "",
+  website: "",
+  update: "",
+  size: "1 MB",
+  more: "",
+  tags: "",
+  img_urls: [],
+  icons: "",
+  category,
+  origin: "spark",
+  currentStatus: "not-installed",
+});
+
+const createApps = (count: number, category: string): App[] =>
+  Array.from({ length: count }, (_, index) => createApp(index, category));
+
+describe("AppGrid", () => {
+  it("resets the virtual scroller when the category changes", async () => {
+    const { container, rerender } = render(AppGrid, {
+      props: {
+        apps: createApps(60, "development"),
+        loading: false,
+        scrollKey: "development",
+      } as Record<string, unknown>,
+    });
+
+    const scroller = container.querySelector(".scroller");
+
+    expect(scroller).toBeInstanceOf(HTMLElement);
+
+    if (!(scroller instanceof HTMLElement)) {
+      throw new Error("Expected virtual scroller element to exist");
+    }
+
+    scroller.scrollTop = 240;
+    expect(scroller.scrollTop).toBe(240);
+
+    await rerender({
+      apps: createApps(60, "games"),
+      loading: false,
+      scrollKey: "games",
+    } as Record<string, unknown>);
+    await nextTick();
+
+    expect(scroller.scrollTop).toBe(0);
+  });
+});