Implement sleep mode functionality for Cthulhu

Add application-specific sleep mode that disables speech and events while preserving the ability to toggle back to normal operation.

Features:
- Keybinding: Cthulhu+Ctrl+Alt+Shift+Q (matches Orca)
- Per-application scope (only affects focused app)
- Suppresses all speech, braille, and event processing
- Preserves sleep mode toggle keybinding for exit
- Status messages on enter/exit

Implementation:
- New sleepmode script module in src/cthulhu/scripts/sleepmode/
- Toggle handler in default.py using script manager
- Proper autotools integration with correct installation paths
- Build system fixes for module discovery

Files modified:
- src/cthulhu/common_keyboardmap.py: Add sleep mode keybinding
- src/cthulhu/scripts/default.py: Add toggleSleepMode handler
- src/cthulhu/scripts/sleepmode/: Complete sleep mode implementation
- CLAUDE.md: Documentation for build system and sleep mode
- Fix sleepmode/Makefile.am installation path

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

distro-packages/Arch-Linux/PKGBUILD

@@ -27,6 +27,7 @@ depends=(
   python-gobject
   python-pluggy
   python-setproctitle
+  python-dasbus
   socat
   speech-dispatcher
   xorg-xkbcomp