dev.cam_xeye.image.put(composite) failed on real hardware --
PreviewSignal is a BECMessageSignal subclass, and BEC hardcodes
rpc_access=False for that signal_info, so the client-side device proxy
never exposes `image` as an attribute at all (confirmed: this is a
structural BEC constraint, not specific to this device -- no existing
RPC surface, device or widget, offers a raw-array setter either).
Add IDSCamera.push_preview_image(data), a small device-server-side
method (alongside the existing get_last_image()) that does
self.image.put(data) from within the device-server process, where
PreviewSignal is a normal ophyd attribute. _push_smear_composite now
calls dev.cam_xeye.push_preview_image(composite) instead of writing to
the signal directly.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
