fix: support macOS 13 and add English/Korean localization

[122yjs]

Summary

• compile the Swift executable with the macOS deployment target declared in Info.plist
• make English the app's development/default language and add Korean localization
• localize the SwiftUI window, menu-bar menu, alerts, notifications, help text, and Apple Events permission text
• copy en.lproj and ko.lproj resources without inherited extended attributes
• add build checks for localization key parity, format-placeholder parity, Chinese UI literals, resource inclusion, code signing, and Mach-O minos
• remove the iconutil step that fails on macOS 15 Sequoia and use the standard macOS app icon

Problem

The v2.2.0 release declares LSMinimumSystemVersion=13.0, but its executable was built with LC_BUILD_VERSION minos 26.0, so macOS 15 Sequoia refuses to launch it. The existing interface is also hard-coded in Chinese.

Language behavior

• English: development language and fallback
• Korean: selected automatically when Korean is preferred in macOS
• Unsupported preferred languages: fall back to English

Verification

Tested on macOS 15.7.7 Sequoia (24G720), Apple Silicon (arm64), Apple Swift 6.1.2, and macOS SDK 15.5.

$ ./check.sh
Localization checks passed: English default, Korean available
Checks passed: macOS deployment target 13.0

English preference:
Never Sleep | Restore Normal | Current Status | Quit KeepAgentAwake

Korean preference:
잠자기 방지 | 기본 상태로 복원 | 현재 상태 | KeepAgentAwake 종료

Unsupported preference (French):
falls back to English

Additional checks:

• Swift type-check and full app compilation pass
• all plist and .strings files pass plutil -lint
• English and Korean key sets and format placeholders match
• every statically detectable tr()/trf() key exists
• built and extracted app bundles contain both localization directories
• ad-hoc signature verification passes
• built and extracted executable retain minos 13.0

Closes #2

[122yjs]

Superseded by the dedicated localization PR #4. Please review #4 instead.