feat: 内置阅读器、批注笔记与 AI 助手，发布 1.3.0

新增 PDF/EPUB/MOBI/AZW 内置阅读器，PDF 分段读取支持超大文件，
批注、读书与画布笔记、封面生成与本地导入。AI 助手支持三种协议、
图像上下文与安全 Markdown 渲染，上下文范围改为 选中/当前页/全文，
页面与全文无需选中文本即可发送，全文会提示可能超出模型限制。

便携版输出目录固定为 PeopleLib-windows-x64，不再随版本号变化，
避免升级后 data/ 被遗留在旧目录。

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

src/library/local-import.js

@@ -0,0 +1,147 @@
+const fs = require('fs/promises');
+const path = require('path');
+
+const BOOK_EXT = new Set([
+  'pdf',
+  'epub',
+  'mobi',
+  'azw',
+  'azw3',
+  'txt',
+  'djvu',
+  'fb2',
+  'cbz',
+  'cbr'
+]);
+const DEFAULT_MAX_FILES = 10_000;
+
+function pathKey(value) {
+  return process.platform === 'win32' ? value.toLowerCase() : value;
+}
+
+function comparePaths(left, right) {
+  const leftKey = pathKey(left);
+  const rightKey = pathKey(right);
+  if (leftKey < rightKey) return -1;
+  if (leftKey > rightKey) return 1;
+  if (left < right) return -1;
+  if (left > right) return 1;
+  return 0;
+}
+
+async function safeLstat(value) {
+  try {
+    return await fs.lstat(value);
+  } catch (error) {
+    return null;
+  }
+}
+
+async function canonicalEntry(value, expectedType) {
+  const before = await safeLstat(value);
+  if (!before || before.isSymbolicLink() || !before[expectedType]()) return null;
+
+  let canonical;
+  try {
+    canonical = await fs.realpath(value);
+  } catch (error) {
+    return null;
+  }
+
+  // Recheck the directory entry after realpath so an entry changed to a link
+  // during discovery is not intentionally traversed or imported.
+  const after = await safeLstat(value);
+  if (!after || after.isSymbolicLink() || !after[expectedType]()) return null;
+  return path.resolve(canonical);
+}
+
+function maximumFrom(options) {
+  if (options && Object.prototype.hasOwnProperty.call(options, 'maxFiles')) {
+    const maximum = options.maxFiles;
+    if (!Number.isSafeInteger(maximum) || maximum < 1) {
+      throw new TypeError('本地导入文件数量上限必须是正整数');
+    }
+    return maximum;
+  }
+  return DEFAULT_MAX_FILES;
+}
+
+async function discover(paths, options = {}) {
+  const maximum = maximumFrom(options);
+  const selected = Array.isArray(paths) ? paths : [paths];
+  const candidates = selected
+    .filter((value) => typeof value === 'string' && value.length > 0)
+    .map((value) => path.resolve(value))
+    .sort(comparePaths);
+
+  const records = [];
+  const seenFiles = new Set();
+  const visitedDirectories = new Set();
+
+  function addFile(canonical) {
+    const key = pathKey(canonical);
+    if (seenFiles.has(key)) return;
+    if (records.length >= maximum) {
+      throw new Error(`本地导入文件数量超过上限（最多 ${maximum} 个）`);
+    }
+
+    seenFiles.add(key);
+    const name = path.basename(canonical);
+    records.push({
+      path: canonical,
+      name,
+      format: path.extname(name).slice(1).toLowerCase(),
+      parentName: path.basename(path.dirname(canonical))
+    });
+  }
+
+  async function visitFile(value) {
+    const extension = path.extname(value).slice(1).toLowerCase();
+    if (!BOOK_EXT.has(extension)) return;
+    const canonical = await canonicalEntry(value, 'isFile');
+    if (canonical) addFile(canonical);
+  }
+
+  async function visitDirectory(value) {
+    const canonical = await canonicalEntry(value, 'isDirectory');
+    if (!canonical) return;
+
+    const key = pathKey(canonical);
+    if (visitedDirectories.has(key)) return;
+    visitedDirectories.add(key);
+
+    let entries;
+    try {
+      entries = await fs.readdir(canonical, { withFileTypes: true });
+    } catch (error) {
+      return;
+    }
+    entries.sort((left, right) => comparePaths(left.name, right.name));
+
+    for (const entry of entries) {
+      const child = path.join(canonical, entry.name);
+      const stat = await safeLstat(child);
+      if (!stat || stat.isSymbolicLink()) continue;
+      if (stat.isDirectory()) {
+        await visitDirectory(child);
+      } else if (stat.isFile()) {
+        await visitFile(child);
+      }
+    }
+  }
+
+  for (const candidate of candidates) {
+    const stat = await safeLstat(candidate);
+    if (!stat || stat.isSymbolicLink()) continue;
+    if (stat.isDirectory()) {
+      await visitDirectory(candidate);
+    } else if (stat.isFile()) {
+      await visitFile(candidate);
+    }
+  }
+
+  records.sort((left, right) => comparePaths(left.path, right.path));
+  return records;
+}
+
+module.exports = { discover };