feat: add tray hotkeys and audio device controls

[Orinks]

Summary

• add AccessiClock system tray support with text menu actions for show, announce time, test chime, settings, and exit
• add configurable announce-time global hotkey support with a safe default of Ctrl+Alt+T when enabled
• add sound_lib audio output device enumeration/selection, a keyboard-friendly Audio Device dialog, and Settings controls
• persist tray, hotkey, and audio-device settings through the uv-enabled config path

Verification

• uv sync --group dev
• uv run pytest -q
• uv run ruff check src tests
• uv run mypy src
• wx runtime accessibility smoke for main labels, Settings controls, Audio Device dialog names/defaults
• wx tray runtime smoke for tray creation and tray action dispatch

Accessibility

• visible text labels for all new controls and tray commands
• keyboard-reachable Audio Device button/dialog and Settings controls
• status text updates for tray/hotkey/audio-device actions
• no unlabeled icon-only UI added