feat: TypeScript + Electron v2 重构 - 纯桌面版

- 全面迁移到 TypeScript，严格类型定义
- 放弃 Web 版，专注 Electron 桌面应用
- 主进程模块化：main.ts, preload.ts, menu.ts, tray.ts, ipc.ts, utils.ts
- 渲染进程完整迁移所有功能组件
- 删除 PWA 相关文件 (sw.js, manifest.json)
- 删除 Web 版降级逻辑
- 保留所有核心功能：流式对话、多模型、Think推理、多模态、RAG知识库、Agent预设、历史管理
- 保留 Windows 11 Fluent Design 暗色主题样式

src/renderer/utils/utils.ts

@@ -0,0 +1,115 @@
+/**
+ * Utils - 通用工具函数
+ */
+
+/** 生成唯一 ID */
+export function generateId(): string {
+  return `${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
+}
+
+/** 格式化时间戳 */
+export function formatTime(ts: number): string {
+  const d = new Date(ts);
+  const pad = (n: number): string => String(n).padStart(2, '0');
+  return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())} ${pad(d.getHours())}:${pad(d.getMinutes())}`;
+}
+
+/** 截断文本 */
+export function truncate(str: string, len = 50): string {
+  if (!str) return '';
+  return str.length > len ? str.substring(0, len) + '...' : str;
+}
+
+/** 防抖 */
+export function debounce<T extends (...args: unknown[]) => unknown>(fn: T, ms = 300): (...args: Parameters<T>) => void {
+  let timer: ReturnType<typeof setTimeout>;
+  return (...args: Parameters<T>) => {
+    clearTimeout(timer);
+    timer = setTimeout(() => fn(...args), ms);
+  };
+}
+
+/** 格式化字节大小 */
+export function formatSize(bytes: number): string {
+  if (!bytes) return '';
+  const units = ['B', 'KB', 'MB', 'GB', 'TB'];
+  let i = 0;
+  let size = bytes;
+  while (size >= 1024 && i < units.length - 1) {
+    size /= 1024;
+    i++;
+  }
+  return `${size.toFixed(1)} ${units[i]}`;
+}
+
+/** HTML 转义 */
+export function escapeHtml(str: string): string {
+  const map: Record<string, string> = { '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' };
+  return String(str).replace(/[&<>"']/g, (c) => map[c]);
+}
+
+/** 下载文件 */
+export function downloadFile(filename: string, content: string, type: string): void {
+  const blob = new Blob([content], { type: type + ';charset=utf-8' });
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement('a');
+  a.href = url;
+  a.download = filename;
+  a.click();
+  URL.revokeObjectURL(url);
+}
+
+/** File → Base64（去前缀） */
+export function fileToBase64(file: File): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onload = () => {
+      const result = reader.result as string;
+      const base64 = result.split(',')[1];
+      resolve(base64);
+    };
+    reader.onerror = reject;
+    reader.readAsDataURL(file);
+  });
+}
+
+/** File → 文本内容 */
+export function fileToText(file: File): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onload = () => resolve(reader.result as string);
+    reader.onerror = reject;
+    reader.readAsText(file);
+  });
+}
+
+/** 根据文件名检测语言标识（用于 Markdown 代码块） */
+export function detectLanguage(filename: string): string {
+  const ext = filename.split('.').pop()?.toLowerCase() || '';
+  const map: Record<string, string> = {
+    py: 'python', pyw: 'python', pyi: 'python',
+    js: 'javascript', mjs: 'javascript', cjs: 'javascript',
+    ts: 'typescript', tsx: 'tsx', jsx: 'jsx',
+    java: 'java', class: 'java',
+    c: 'c', h: 'c',
+    cpp: 'cpp', cc: 'cpp', cxx: 'cpp', hpp: 'cpp',
+    go: 'go', rs: 'rust', rb: 'ruby', php: 'php',
+    sh: 'bash', bash: 'bash', zsh: 'bash', fish: 'bash',
+    sql: 'sql', html: 'html', htm: 'html', css: 'css',
+    json: 'json', jsonl: 'json',
+    xml: 'xml', svg: 'svg',
+    yaml: 'yaml', yml: 'yaml', toml: 'toml',
+    ini: 'ini', cfg: 'ini', conf: 'ini',
+    md: 'markdown', markdown: 'markdown', rst: 'rst',
+    txt: '', csv: 'csv', tsv: 'csv', log: '',
+    swift: 'swift', kt: 'kotlin', kts: 'kotlin',
+    scala: 'scala', lua: 'lua', pl: 'perl', r: 'r',
+    m: 'matlab', mm: 'objectivec',
+    cs: 'csharp', fs: 'fsharp', vb: 'vbnet',
+    ex: 'elixir', exs: 'elixir', erl: 'erlang',
+    hs: 'haskell', clj: 'clojure', lisp: 'lisp',
+    dockerfile: 'dockerfile', makefile: 'makefile',
+    diff: 'diff', patch: 'diff',
+  };
+  return map[ext] ?? ext;
+}