[feat](build): add versioned Docker image build script and version injection

- Introduced `tools/build_server_image.sh` for building versioned server images with support for multi-arch builds.
- Added `VERSION` injection via `-ldflags` in Dockerfile and Go binaries for both server and client.
- Updated workflows and Makefile to ensure consistent version tagging during builds.

.github/workflows/docker-publish.yml

@@ -56,4 +56,6 @@ jobs:
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
-          cache-to: type=gha,mode=max
+          cache-to: type=gha,mode=max
+          build-args: |
+            VERSION=${{ github.sha }}