feat: add local Docker build script and update compose configuration

- Introduced a new script `docker-build-local.sh` to build a local Docker image and start services using Docker Compose.
- Updated `docker-compose.yml` to allow dynamic pull policy configuration via the `CLI_PROXY_PULL_POLICY` environment variable.
- Modified `Dockerfile` to support build arguments for Go module proxy settings during the `go mod download` step.

docker-compose.yml

@@ -1,7 +1,7 @@
 services:
   cli-proxy-api:
     image: ${CLI_PROXY_IMAGE:-eceasy/cli-proxy-api:latest}
-    pull_policy: always
+    pull_policy: ${CLI_PROXY_PULL_POLICY:-always}
     build:
       context: .
       dockerfile: Dockerfile