feat: migrate configuration to system location

✅ Configuration Migration
- Moved configs from /opt/aitbc/config to /etc/aitbc
- Moved production .env to /etc/aitbc/production.env
- Updated all code references to use /etc/aitbc
- Updated systemd services to use /etc/aitbc
- Removed config files from git tracking
- Updated .gitignore for config files

✅ System Compliance
- All configuration now in /etc/aitbc (FHS compliant)
- No configuration files in repository
- Proper system-wide configuration location
- Security-sensitive files in system location

✅ Service Updates
- Production services use /etc/aitbc/production.env
- SystemD services use /etc/aitbc/.env
- All code references updated to system paths
- Services restart and test successfully

🚀 AITBC configuration now follows proper system standards!

.gitignore

@@ -318,3 +318,8 @@ data/
 *.log
 production/data/
 production/logs/
+config/
+*.env
+api_keys.txt
+*.yaml
+!*.example