fix(desktop): fit main window to small work areas - #764

Summary / 摘要

• Fit first-launch and restored main-window geometry to the selected display work area.
• Cap effective minimum dimensions to displays smaller than the configured minimum while preserving the configured minimum on normal displays.
• Preserve saved positioning when valid, let Electron place an unsaved first window, and fall back safely if state or screen lookup fails.
• Add pure geometry and Electron-runtime regression coverage for small displays, corrupt state, and screen API failures.

Related Issues / 关联 Issue

N/A — found during local inspection.

Type / 类型

• Bug fix / Bug 修复
• Feature / 新功能
• Refactor / 重构
• Documentation / 文档
• Tests / 测试
• Chore / 维护

Platforms / 影响平台

• Not platform-specific / 非平台特定
• Windows installer / Windows 安装版
• Windows portable / Windows 便携版
• macOS
• Linux

Verification / 验证

• corepack yarn check:layout
• corepack yarn typecheck
• corepack yarn test
• corepack yarn check
• Platform package smoke / 平台打包冒烟
• Manual test / 手工测试

Additional verification:

• Focused desktop regression suites: 84/84 passed.
• Desktop full suite: 970 passed, 12 skipped, 13 failed due to Windows-host constraints/flakes unrelated to this diff (10 symlink privilege errors, missing pnpm in one packaged fixture, one lifecycle timeout, and one atomic-rename EPERM).
• Root corepack yarn check passed documentation/layout checks, Market build and 268/268 Market tests, Desktop build, and Desktop typecheck; it stopped at the same 13 Desktop environment failures.
• git diff --check passed.
• Independent review found no blocking or non-blocking findings.

Manual Windows monitor-disconnect smoke testing passed: the window was saved on a secondary display, restarted with only the primary display enabled, and remained fully visible after being fitted to the primary work area. High-DPI/RDP was not tested separately.

Release Notes / 发布说明

The Desktop main window now stays within the available display work area on small, scaled, and remote-desktop displays. No migration or configuration change is required.