feat: migrate to DragonflyDB and clean up environment configuration

- Replace Redis with DragonflyDB for better performance and memory efficiency
- Remove redundant environment variables (POSTGRES_*, ENCRYPTION_KEY, OAUTH_SERVICE_URL)
- Consolidate database configuration to use single DB_* variables
- Use JWT_SECRET for both JWT tokens and encryption
- Remove PORT variable redundancy, use BACKEND_PORT consistently
- Clean up docker-compose configurations for dev/prod consistency
- Add DragonflyDB configuration with optimized memory usage
- Remove redis.conf as it's no longer needed
- Update health checks to use Redis-compatible CLI for DragonflyDB
- Add missing VITE_API_URL to production frontend
- Fix GitHub Actions to use correct go.sum path
- Clean up development directories and unused files

docker-compose.demo.yml

@@ -0,0 +1,54 @@
+services:
+  trackeep-backend:
+    build:
+      context: ./backend
+      dockerfile: Dockerfile
+    ports:
+      - "${BACKEND_PORT:-8080}:${BACKEND_PORT:-8080}"
+    env_file:
+      - .env
+    environment:
+      - APP_VERSION=${APP_VERSION:-1.0.0}
+      - BACKEND_PORT=${BACKEND_PORT:-8080}
+      - FRONTEND_PORT=${FRONTEND_PORT:-8080}
+      - VITE_DEMO_MODE=true
+    volumes:
+      - ./data:/data
+      - ./uploads:/app/uploads
+      - /var/run/docker.sock:/var/run/docker.sock  # Docker socket for updates
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD-SHELL", "wget --no-verbose --tries=1 --spider http://localhost:${BACKEND_PORT:-8080}/health || wget --no-verbose --tries=1 --spider http://localhost:${BACKEND_PORT:-8080}/live"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
+
+  trackeep-frontend:
+    build:
+      context: .
+      dockerfile: ./frontend/Dockerfile
+      args:
+        - VITE_DEMO_MODE=true
+        - VITE_API_URL=${VITE_API_URL:-http://localhost:8080}
+        - VITE_OAUTH_SERVICE_URL=${VITE_OAUTH_SERVICE_URL:-https://oauth.trackeep.org}
+    ports:
+      - "${FRONTEND_PORT:-3000}:${FRONTEND_PORT:-3000}"
+    environment:
+      - VITE_APP_VERSION=${APP_VERSION:-1.0.0}
+      - VITE_DEMO_MODE=true
+      - VITE_API_URL=${VITE_API_URL:-http://localhost:8080}
+      - VITE_OAUTH_SERVICE_URL=${VITE_OAUTH_SERVICE_URL:-https://oauth.trackeep.org}
+      - FRONTEND_PORT=${FRONTEND_PORT:-3000}
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock  # Docker socket for updates
+    depends_on:
+      trackeep-backend:
+        condition: service_healthy
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD-SHELL", "pgrep nginx > /dev/null || exit 1"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 20s