New option (default OFF) that compiles only jfjoch_viewer and the
libraries it transitively links -- common, image_analysis, writer,
reader, preview, image_puller, frame_serialize, gemmi_gph, compression,
jungfrau, and the OpenAPI model (JFJochAPI) -- skipping the Linux-only
online stack (broker service, receiver, fpga, acquisition_device,
detector_control, image_pusher, xds-plugin, tests, tools) and the
frontend. This is the standalone build path for the cross-platform
viewer.
JFJochAPI is the only piece the viewer needs from broker/, so the broker
service library and executable are gated behind NOT JFJOCH_VIEWER_ONLY.
The full build and JFJOCH_VIEWER_BUILD (viewer on top of the full build)
are unchanged -- that path is the verbatim ELSE() branch.
Verified on Linux: cmake -DJFJOCH_VIEWER_ONLY=ON configures and
`make jfjoch_viewer` links cleanly with the online stack absent.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>