桌面下载端改用共享核心包，并修两处已知缺陷

- store 改由 createGalleryStore 生成：totalGalleryTask 成为唯一任务源，
  收藏/下载/分类/搜索结果全部由 getter 派生，不再维护三份互相引用的数组
- 排序不再原地修改分类数组；本地搜索记住关键词，任务刷新后结果仍在
- 本地搜索结果补齐翻页入口：此前匹配 25 项却只显示 10 项，其余无法看到
- 取消收藏不再因本地找不到 gid 抛 TypeError
- 删除重复的 taskSocket/progressiveImages/validate/thumbnail，改从共享包导入
- 远端搜索改用共享 fetchGalleries，关键词交给 axios 序列化，翻页按游标转发
- main.js 按需注册 Element Plus，入口 JS 由约 1.14MB 降到约 494KB
- 依赖新增 file:../lionwebsite-frontend-shared

测试：14 项通过；构建成功，入口仍为 /asserts/index/index.js|css。

tests/search.test.mjs

@@ -0,0 +1,37 @@
+import test from "node:test"
+import assert from "node:assert/strict"
+import {buildSearchParams, fetchGalleries, readResponse} from "lionwebsite-frontend-shared"
+
+test("keyword request never hand-builds the query string", () => {
+    assert.deepEqual(buildSearchParams({keyword: "cat girl"}), {keyword: "cat girl"})
+})
+
+test("next page forwards the upstream cursor instead of the keyword", () => {
+    const params = buildSearchParams({
+        keyword: "cat girl", direction: "next",
+        href: "https://exhentai.org/?f_search=cat+girl&next=777",
+    })
+    assert.equal(params.next, "777")
+    assert.equal(params.keyword, "cat girl")
+})
+
+test("fetchGalleries decodes object and JSON-string payloads identically", async () => {
+    const asObject = {get: async () => ({data: {result: "success", data: [{gid: 1}], next: "n1"}})}
+    const asString = {get: async () => ({data: {result: "success", data: '[{"gid":1}]', next: "n1"}})}
+    const one = await fetchGalleries(asObject, {keyword: "k"})
+    const two = await fetchGalleries(asString, {keyword: "k"})
+    assert.deepEqual(one.galleries, two.galleries)
+    assert.equal(one.pagination.next, "n1")
+})
+
+test("fetchGalleries surfaces the backend message on failure", async () => {
+    const http = {get: async () => ({data: {result: "failure", data: "没有搜索到结果"}})}
+    await assert.rejects(() => fetchGalleries(http, {keyword: "k"}),
+        error => error.payload === "没有搜索到结果")
+})
+
+test("readResponse keeps all four pagination cursors", () => {
+    const parsed = readResponse({data: {result: "success", data: "[]",
+        first: "f", previous: "p", next: "n", last: "l"}})
+    assert.deepEqual(parsed.pagination, {first: "f", previous: "p", next: "n", last: "l"})
+})