v4.0.1

What's Changed

• add new banner by @Sandip124 in #86
• Add CodeQL analysis workflow configuration by @Sandip124 in #90
• Expr/avalonia by @Sandip124 in #91

What's New

Battery Monitoring

• Instant charger detection — event-driven architecture using WMI events (Windows) and Darwin notifications (macOS) for immediate plug/unplug response,
  with lightweight polling as fallback
• Smarter notification rules — full battery alerts only fire when charger is plugged in; unplugging above threshold no longer triggers spurious
  notifications
• Clear time estimates — "45m to full charge" (charging) / "3h 20m of battery remaining" (discharging) instead of ambiguous "45m remaining"
• Contextual status messages — replaced generic jokes with battery-aware fallbacks like "Charging — estimating time to full..." when OS can't provide
  an estimate

Sound System

• Custom sounds library — import your own .wav, .mp3, .m4a, .ogg, .flac, or .aac files; they're copied to the app's data directory and persist across
  sessions
• Editor's Choice sounds — 6 curated music clips bundled with the app (Rock N Roll, Admonition, Snowy Glow, Legacy)
• Full playback for custom sounds — imported and bundled sounds play once in full instead of being clipped; built-in tones still loop
• Delete imported sounds — remove custom sounds from the library via the X button in the sound picker

DND / Focus Mode

• macOS Tahoe support — DND detection works on macOS 16 via Control Center accessibility fallback
• DND indicator in UI — banner shows between battery info and quick settings when Focus mode is active
• Near real-time monitoring — Darwin notification polling every 5s (zero-cost memory read) with 2-minute fallback

Logging

• Structured logs at every key point: power line changes, battery level changes, notification publish/suppress/deliver decisions, DND suppression state

Code Quality

• Centralized hardcoded paths into Constants.AppName, Constants.AppDataDirectory, Constants.AppTempDirectory
• Centralized asset URIs into AssetUris (Logo48, Logo128, LogoIco, ForAsset, ForSound)
• Sealed 15 non-derived classes for performance
• Refactored high-complexity methods: UpdateCheckIcons, CheckBatteryAndPowerStatus, IsMacDoNotDisturbActive
• Added 1-second regex timeouts across all Regex calls (ReDoS prevention)
• Subprocess commands resolved to absolute paths via Constants.ResolveCommand() (avoids PATH injection)
• Debouncer: exception handling in timer callback + race condition fix (invoke inside lock)
• AppSettings: error paths now call Reset() instead of Save() to properly restore defaults
• Removed dead code: unused logger, no-op event unsubscription, stale IDE mappings

CI/CD

• Fixed signtool not found — locates it from Windows SDK path
• Secrets passed via env: blocks (not expanded in run: blocks)
• Graceful skip when signing secrets aren't configured
• Certificate/keychain cleanup via try/finally and trap EXIT
• Binary validation before signing (fail fast with clear error)
• Post-sign verification (codesign --verify --deep --strict)
• Timestamp URL upgraded to HTTPS
• Version read from csproj via MSBuild (no hardcoded fallback)
• Velopack CLI pinned to 0.0.1298
• Linux builds disabled in CI
• bump-version.sh fixed for macOS (grep/sed compatibility)

Security

• Settings encryption documented accurately: DPAPI on Windows, AES-256-GCM on macOS/Linux
• CustomSoundsLibrary.Import(): extension allowlist, 50MB limit, symlink rejection, atomic write, collision handling

Full Changelog: v3.1.1...v4.0.0