v3_nodes.py builds a V3 io.ComfyNode per V1 class from its INPUT_TYPES/
RETURN_TYPES and delegates execute() to the V1 method (no forked logic),
including the StringPreview OUTPUT_NODE ui.PreviewText path. comfy_entrypoint
exported import-guarded. StringMultiReplace use_regex now raises a clear
ValueError naming the bad pattern instead of a raw re.error. Added tooltips
to strip/multi_replace boolean flags. Verified ComfyUI 0.25.0.
