refactor: major repository cleanup and simplification

Remove version suffixes and streamline structure:
- Rename all bridge files (remove -v2 suffix)
  * matter_mqtt_bridge_v2.py → matter_mqtt_bridge.py
  * bridge-config-v2.yaml → bridge-config.yaml
  * docker-compose-v2.yml → docker-compose.yml
  * Dockerfile.bridge-v2 → Dockerfile
- Archive legacy v1 implementation to archive/v1-legacy/
- Update all file references in docker-compose.yml and configs

Streamline documentation (7 files → 2 focused docs):
- Keep: docs/INTEGRATION.md (renamed from HABAPP_MQTT_INTEGRATION.md)
- Create: docs/TROUBLESHOOTING.md (comprehensive troubleshooting guide)
- Remove: MATTER_SETUP_ANALYSIS.md (12,000+ words), QUICK_START_GUIDE.md,
  MQTT_BRIDGE_COMPARISON.md, MDNS_DISCOVERY_GUIDE.md,
  ANSWERS_TO_YOUR_QUESTIONS.md, docs/README.md

Clean scripts (8 files → 2 essential + Web UI):
- Keep: setup-ipv6.sh (critical), monitor-sensors.sh (useful)
- Remove: commission_device.py, commission_simple.py, read_temp.py,
  sync_time.py, install_cron.sh
- Recommend: Matter Server Web UI at http://localhost:5580 for commissioning

Update documentation:
- Rewrite bridge/README.md (515 lines → 130 focused lines)
- Update scripts/README.md to focus on 2 scripts + Web UI
- Update main README.md with new structure and links
- Remove planning documents (cleanup complete)

BREAKING CHANGE: File paths changed. Update local deployments:
- bridge-config-v2.yaml → bridge-config.yaml
- Dockerfile.bridge-v2 → Dockerfile
- bridge/docker-compose-v2.yml → bridge/docker-compose.yml

Author: jenicek001