Phase 9 Complete: Cleanup & Documentation

Completed:
- Created INSTALL.md with concise sysadmin-focused guide
- Updated README.md troubleshooting to reference INSTALL.md
- Marked ROADMAP Phase 9 complete

Documentation Philosophy:
- Compact and practical
- Assumes sysadmin familiarity
- Focus on actual usage, not theory

All 9 phases of migration now complete!

readme.md

@@ -22,7 +22,7 @@ Raspberry Pi service that monitors Xiaomi Mijia LYWSD03MMC Bluetooth temperature
 
 ## Installation
 
-See [SETUP_ON_PI.md](SETUP_ON_PI.md) for complete installation instructions.
+See [INSTALL.md](INSTALL.md) for complete installation instructions.
 
 ### Quick Start
 
@@ -158,56 +158,25 @@ sensorpajen/
 
 ## Troubleshooting
 
-### Permission Denied Errors
+See [INSTALL.md](INSTALL.md#troubleshooting) for detailed troubleshooting steps.
 
-If you see `PermissionError: [Errno 1] Operation not permitted`:
+### Quick Checks
 
+**Permission errors:**
 ```bash
-# Verify capabilities are set
-getcap $(readlink -f ~/sensorpajen/.venv/bin/python3)
-
-# Should show: cap_net_admin,cap_net_raw+eip
-# If not, set them:
 sudo setcap 'cap_net_raw,cap_net_admin+eip' $(readlink -f ~/sensorpajen/.venv/bin/python3)
-
-# Restart service
 systemctl --user restart sensorpajen
 ```
 
-### Service Won't Start
-
+**Service status:**
 ```bash
-# Check service status
 systemctl --user status sensorpajen
-
-# View logs
-journalctl --user -u sensorpajen -n 50
-
-# Common issues:
-# - Missing config files (check config/ directory)
-# - Wrong MQTT credentials (check config/sensorpajen.env)
-# - Bluetooth not enabled (sudo systemctl start bluetooth)
+journalctl --user -u sensorpajen -f
 ```
 
-### MQTT Connection Issues
-
+**MQTT test:**
 ```bash
-# Test MQTT connection
-mosquitto_sub -h <MQTT_HOST> -u <USERNAME> -P <PASSWORD> -t "MiTemperature2/#" -v
-
-# Check logs for connection errors
-journalctl --user -u sensorpajen | grep -i mqtt
-```
-
-### No Sensor Data
-
-```bash
-# Check if sensors are visible
-sudo hcitool lescan
-
-# Verify sensor MAC addresses in config/sensors.json
-# Make sure sensors have ATC firmware flashed
-# Check battery level (low battery can cause connection issues)
+mosquitto_sub -h <MQTT_HOST> -u <USER> -P <PASSWORD> -t "MiTemperature2/#" -v
 ```
 
 ## Development