fix: prevent settings label layout collapse

[wimi321]

Summary

• fixes the settings checkbox rule that could squeeze labels into one-character vertical columns
• keeps checkbox controls at 16x16 while multilingual label copy uses the available horizontal space
• lets action groups wrap without splitting button text
• separates the automatic-benchmark title and help copy into stable rows
• adds a regression contract for issue [Bug]: 设置页出现样式错位 #31

This integrates the focused UI fix proposed through #47. Thank you @eagleLiu82 for reporting and carrying the contribution. The unrelated 0.4.21 version bump, release notes, tag preparation, and NVIDIA release-script changes from that branch are intentionally excluded.

Visual QA

• real Electron app, isolated temporary profile
• desktop and compact settings layouts
• Go analysis and Zhizi Cloud pages
• seven locales: Simplified Chinese, Traditional Chinese, English, Japanese, Korean, Thai, Vietnamese
• no horizontal content overflow; labels remain horizontal and title/help hierarchy stays intact

Verification

• 256/256 tests passed
• pnpm typecheck passed
• pnpm build passed
• pnpm check passed

Closes #31