chore(config): remove dragonflydb and update deployment documentation

Remove all references to DragonflyDB from the codebase, environment templates, and documentation following its removal from the service architecture. This includes cleaning up Docker configurations, CI/CD workflows, and production guides.

- **Cleanup**: Deleted `dragonfly.conf` and removed DragonflyDB service from `docker-compose.yml`.
- **Environment**: Removed `DRAGONFLY_PASSWORD` and `DRAGONFLY_ADDR` from `.env.example` and `docker-entrypoint.sh`.
- **Documentation**: Updated `README.md`, `PRODUCTION_DEPLOYMENT.md`, and `QUICK_START_PRODUCTION.md` to reflect a 2-service architecture (Trackeep + Postgres).
- **CI/CD**: Updated GitHub Actions to use Go 1.25.
- **Testing**: Updated `test-production.sh` to remove DragonflyDB variable validation.

QUICK_START_PRODUCTION.md

@@ -45,7 +45,6 @@ cp .env.example .env
 echo "JWT_SECRET=$(openssl rand -base64 32)" >> .env
 echo "ENCRYPTION_KEY=$(openssl rand -base64 32)" >> .env
 echo "DB_PASSWORD=$(openssl rand -base64 24)" >> .env
-echo "DRAGONFLY_PASSWORD=$(openssl rand -base64 24)" >> .env
 
 # Edit .env if needed
 nano .env
@@ -332,16 +331,6 @@ WHERE schemaname NOT IN ('pg_catalog', 'information_schema')
 ORDER BY pg_total_relation_size(schemaname||'.'||tablename) DESC;
 ```
 
-### Cache Optimization
-
-```bash
-# Check DragonflyDB stats
-docker-compose -f docker-compose.prod.yml exec dragonfly redis-cli -a $DRAGONFLY_PASSWORD INFO
-
-# Clear cache if needed
-docker-compose -f docker-compose.prod.yml exec dragonfly redis-cli -a $DRAGONFLY_PASSWORD FLUSHALL
-```
-
 ## Monitoring
 
 ### Check Service Health