feat: 实现笔临 P0/P1 Electron 桌面应用 v0.1.0

交付写作核心（TipTap、自动保存、分卷分章）、Onboarding、7 主题与双语 i18n、快捷键设置；主进程使用 node:sqlite；补全 Vitest 与 Playwright E2E；统一 design/ 目录并移除 desigin 拼写错误路径。

Co-authored-by: Cursor <cursoragent@cursor.com>

src/renderer/lib/ipc-client.ts

@@ -0,0 +1,17 @@
+import type { IpcError, IpcResult } from '@shared/types'
+
+export class IpcCallError extends Error {
+  ipcError: IpcError
+
+  constructor(ipcError: IpcError) {
+    super(ipcError.message)
+    this.name = 'IpcCallError'
+    this.ipcError = ipcError
+  }
+}
+
+export async function ipcCall<T>(fn: () => Promise<IpcResult<T>>): Promise<T> {
+  const result = await fn()
+  if (!result.ok) throw new IpcCallError(result.error)
+  return result.data
+}

src/renderer/lib/theme.ts

@@ -0,0 +1,9 @@
+import type { ThemeId } from '@shared/types'
+
+export function applyTheme(theme: ThemeId): void {
+  if (theme === 'default') {
+    document.documentElement.removeAttribute('data-theme')
+  } else {
+    document.documentElement.setAttribute('data-theme', theme)
+  }
+}