Add low disk space warning

[Dezoff-max]

Summary

• warn in the menu bar when available disk space falls below 10%
• add a direct route from the warning to Disk Analysis without starting a scan
• check disk capacity at launch and every 30 minutes
• limit already-authorized macOS notifications to once per 24 hours
• add RU/EN copy and focused threshold/cooldown tests

Safety

• does not request notification permission
• does not start scanning or cleanup automatically
• does not modify user files
• does not change the app version or release assets

Verification

• swift test --package-path CleanMacCore — 43/43 passed
• ./script/build_and_run.sh --verify — build, ad-hoc signature, and launch passed
• RU/EN plist lint and key parity passed
• live requested-section route opened Disk Analysis without starting a scan
• normal current disk capacity keeps the warning hidden
• git diff --check passed