feat(distribution): add clean package build system

- Add scripts/build-package.sh for production-ready packages
- VCS-agnostic archive creation (git/hg/bzr/fossil support)
- Automatic version detection from VERSION file or git tags
- Secure exclusions for development files and secrets
- Package validation and content verification
- Support for explicit version override

Creates dist/furt-api-gateway-vX.Y.Z.tar.gz with clean structure
for deployment without development dependencies.

Related to DAW/furt#88

.gitignore

@@ -16,6 +16,7 @@ logs/
 tmp/
 pid/
 dist/
+scripts/upload-package.sh
 
 # Issue creation scripts (these create issues, don't version them)
 scripts/gitea-issues/