Fix SAM3 loading in desktop ComfyUI installs

[artokun]

Summary

• bootstrap the real ComfyUI core path before
  egister_nodes() runs
• do the same bootstrap inside the isolated
  odes package so older_paths, comfy_api, and other ComfyUI modules resolve under desktop installs
• keep the change local to import/bootstrap logic without changing node behavior

Problem

On desktop ComfyUI installs, comfy-env isolation can scan comfyui-sam3 before the ComfyUI core path is available on sys.path. That causes imports like older_paths to fail during metadata scan, so the node registers 0 nodes even though dependencies are installed.

Validation

• reproduced the failure locally from a desktop ComfyUI installation layout
• verified the patched package imports successfully through
  egister_nodes()
• confirmed local registration reports 15 SAM3 nodes after the fix

[colorrin]

Hopefully this gets merged soon, is there any temporary workaround?

[JoeGaffney]

this comfy-env package seems very problematic rebuilding a unique enviroment again from what it looks like when quickly scaning the code is also loading custom wheels the author made

[artokun]

@colorrin you can use my fork from this PR in the meantime until it gets patched, that's what I am using

[colorrin]

Thanks a lot @artokun, it worked perfectly