An optional source_image socket pads an image from another node instead
of the chosen file, so a step before the pad (flattening a transparent
picture onto white, say) no longer has to be saved and loaded back.
- The wire wins over the file; validation skips the file check while it
is connected and runs core's link-type check itself, since asking for
input_types turns core's off for the node.
- A wired run hands the canvas a small temp preview (one file per node,
overwritten each run) and the true source size, so the stage draws the
last image it padded; before the first run it shows an outline.
- Card rows gain linkedBy, so the Source row dims while a wire replaces it.
- Appended and optional with no widget: saved workflows and API prompts
load unchanged. Node API snapshot refreshed.
ausboss
f32917321e