[codex] Add lock screen and login launch preferences

[srt54558]

Summary

• add a Start Caffeine when logging in preference backed by SMAppService.mainApp
• separate normal launch activation from login-item activation with a new Activate when started at login preference
• add a default-on Deactivate when screen locks preference using the macOS lock notification path
• localize the new preference strings across the existing .lproj resources

Details

Manual Apple menu Lock Screen does not consistently deliver the workspace session resign notification to this menu bar app. The app now also observes the com.apple.screenIsLocked distributed notification and gates that behavior behind a user preference.

Login-item launches are detected from the initial open-application Apple event, so normal manual launches can still auto-activate while login launches stay inactive and quiet unless explicitly enabled.

Validation

• xcodebuild -project src/Caffeine.xcodeproj -scheme Caffeine -configuration Release -destination platform=macOS CODE_SIGNING_ALLOWED=NO build
• plutil -lint src/Caffeine/Resources/*.lproj/Localizable.strings
• git diff --check
• installed locally over /Applications/Caffeine.app with ad-hoc signing and verified screen-lock deactivation behavior

Notes

• The normal signed build could not be used locally because this machine does not have the Mac Development certificate for team 568T6RKXH7.
• swiftformat . could not be run because swiftformat is not installed on this machine.