feat: 新增 PDF 转换服务（epub->pdf，cookie 用户隔离，软删/硬删两级删除）

纯 Python 转换（ebooklib 解析 epub + weasyprint 渲染 HTML/CSS 为 PDF），
无需 calibre/xvfb 系统依赖。复用 UploadedFile 存储（原始文件与产物 PDF）。

- model/dao/schema：PdfJob 记录转换任务（owner_cookie/source/output/进度/状态）
- pdf_converter：epub->PDF 转换器（按 spine 顺序拼 HTML，OPF 目录解析相对资源）
- pdf_service：上传落盘 + asyncio 后台转换（独立 Session）+ 进度追踪 + 两级删除
  · 用户软删（user_deleted，管理页仍可见）· 管理员硬删（真正删磁盘+记录）
- pdf_controller：/api/pdf/*（用户，cookie）+ /api/admin/pdf/*（Basic Auth）
- /pdf、/pdf-admin 页面（原生 JS，复用 common.css/js）
- 配置 pdf 段（max_size 250MB、转换超时、cookie）
- pytest 7 项（SQLite→MySQL 隔离测试库）：上传/转换/下载/软删/硬删/超限/越权

static/pdf_admin.js

@@ -0,0 +1,97 @@
+/* PDF 转换管理页：拉取 /api/admin/pdf/jobs、渲染表格（含「是否已删除」列）、硬删。 */
+(function () {
+  "use strict";
+  const { el, toast, fmtBytes, fmtTime, api } = window.ZK;
+  const listEl = document.getElementById("list");
+  const countEl = document.getElementById("count");
+  const refreshBtn = document.getElementById("refresh");
+
+  refreshBtn.addEventListener("click", load);
+
+  async function load() {
+    listEl.innerHTML = '<div class="skel">加载中…</div>';
+    countEl.textContent = "";
+    try {
+      const res = await api("/api/admin/pdf/jobs?limit=500&offset=0");
+      if (!res.ok) throw new Error("HTTP " + res.status);
+      const body = await res.json();
+      render(body.items || []);
+      countEl.textContent = `共 ${body.total} 个任务`;
+    } catch (e) {
+      listEl.innerHTML = '<div class="empty">加载失败：' + (e.message || e) + "</div>";
+    }
+  }
+
+  function render(items) {
+    if (!items.length) {
+      listEl.innerHTML = '<div class="empty">还没有任务。</div>';
+      return;
+    }
+    const table = el("table", { class: "jobs-table admin-table" });
+    const thead = el("thead", null,
+      el("tr", null,
+        el("th", { class: "col-name" }, "文件名"),
+        el("th", { class: "col-size" }, "大小"),
+        el("th", { class: "col-status" }, "状态"),
+        el("th", { class: "col-del" }, "是否已删除"),
+        el("th", { class: "col-time" }, "创建时间"),
+        el("th", { class: "col-act" }, "操作")
+      )
+    );
+    const tbody = el("tbody", null);
+    for (const j of items) tbody.appendChild(renderRow(j));
+    table.appendChild(thead);
+    table.appendChild(tbody);
+    listEl.innerHTML = "";
+    listEl.appendChild(table);
+  }
+
+  function renderRow(j) {
+    const row = el("tr", { class: j.user_deleted ? "row-soft-deleted" : "" },
+      el("td", { class: "col-name" }, j.source_filename),
+      el("td", { class: "col-size mono" }, fmtBytes(j.source_size)),
+      el("td", { class: "col-status" }, statusCell(j)),
+      el("td", { class: "col-del" }, deletedCell(j)),
+      el("td", { class: "col-time muted" }, fmtTime(j.created_at)),
+      el("td", { class: "col-act" },
+        j.status === "done"
+          ? el("a", { class: "btn", href: `/api/admin/files/${j.output_file_id}/download`, download: "" }, "下载产物")
+          : el("span", { class: "muted" }, "-"),
+        el("button", { class: "btn danger", onclick: () => remove(j, row) }, "硬删")
+      )
+    );
+    return row;
+  }
+
+  function statusCell(j) {
+    if (j.status === "done") return el("span", { class: "tag ok" }, "完成");
+    if (j.status === "failed")
+      return el("span", { class: "tag err", title: j.error_message || "" }, "失败");
+    return el("span", { class: "tag warn" }, j.status === "converting" ? `转换中 ${j.progress}%` : "排队中");
+  }
+
+  function deletedCell(j) {
+    if (j.user_deleted) {
+      return el("span", { class: "tag err", title: fmtTime(j.deleted_at) }, "已删除");
+    }
+    return el("span", { class: "muted" }, "否");
+  }
+
+  async function remove(j, row) {
+    if (!confirm(`确定硬删「${j.source_filename}」？\n将真正删除原始文件与产物 PDF（磁盘 + 记录），不可恢复。`)) return;
+    try {
+      const res = await api(`/api/admin/pdf/jobs/${j.id}`, { method: "DELETE" });
+      if (res.status === 404) { toast("任务已不存在"); }
+      else if (!res.ok) throw new Error("HTTP " + res.status);
+      row.classList.add("row-removed");
+      setTimeout(() => row.remove(), 250);
+      toast("已硬删");
+      const m = (countEl.textContent || "").match(/(\d+)/);
+      if (m) countEl.textContent = `共 ${Math.max(0, Number(m[1]) - 1)} 个任务`;
+    } catch (e) {
+      toast("删除失败：" + (e.message || e), "err");
+    }
+  }
+
+  load();
+})();