Implement Adaptive Lighting Mode System Phase 1 foundation

Add global mode definitions and config button mode cycling blueprint to
establish the foundation for the adaptive lighting mode system.

Changes:
- Add input_text helpers for all 11 mode settings (Adaptive, Reading,
  Relaxing, Sleep, Theater, Party, Homework, Play, Cooking, Dining,
  Cleanup) with JSON configuration for brightness, color temp, and
  transition parameters
- Store mode settings as individual input_text entities to work within
  Home Assistant's 255 character limit
- Add usage notes for accessing mode settings in templates
- Fix variable definition bug in inovelli_mode_cycling blueprint by
  adding zigbee2mqtt_device_name to variables section
- Update README to reflect that PACKAGE_SETUP_GUIDE.md exists

All YAML files validated with yamllint. JSON configuration validated
with jq.

Part of Phase 1 implementation from adaptive lighting mode system plan.
Automated verification complete, ready for manual testing.

README.md

@@ -27,7 +27,7 @@ A comprehensive mode-based lighting control system for Inovelli Blue Dimmer Swit
 
 ### Quick Start
 
-See [PACKAGE_SETUP_GUIDE.md](PACKAGE_SETUP_GUIDE.md) for detailed setup instructions (coming soon).
+See [PACKAGE_SETUP_GUIDE.md](PACKAGE_SETUP_GUIDE.md) for detailed setup instructions.
 
 **Prerequisites**:
 - Home Assistant with Adaptive Lighting integration installed