Local build via Docker git context required `git` in the BuildKit worker,
which QNAP Container Station and Synology DSM don't provide. Both sidecar
images are now published to ghcr.io/maziggy/{orca-slicer-api,bambu-studio-api}
and docker.io/maziggy/{orca-slicer-api,bambu-studio-api}; compose pulls
:latest by default, SIDECAR_TAG=bambuddy-X.Y.Z pins per release.
Wiki, slicer-api README, .env.example, and CHANGELOG aligned. Build-from-source
path kept under "Building from source (advanced)" for forks / dev work.
Both images are linux/amd64 only — OrcaSlicer ARM64 on hold pending upstream
fix; BambuStudio doesn't publish ARM64.