Fix editable install scanning 6,500+ node_modules dirs (#4697)

* fix: scope packages.find to prevent node_modules namespace scanning

The packages.find section had no include filter, so setuptools'
find_namespace_packages discovered all directories as potential Python
packages -- including the 6,557 directories inside
studio/frontend/node_modules/ after the frontend build step.

This caused the editable install overlay step to run 20,000+ glob
operations across 6,619 "packages", which on fast NVMe takes ~5s but
on slower disks can take 7+ minutes.

Adding an explicit include filter scopes discovery to only the packages
we actually ship (unsloth, unsloth_cli, studio, studio.backend), dropping
from 6,619 to 58 discovered packages and the editable build time from
5.4s to 1.2s.

Also removes the broken kernels/moe exclude (used "/" instead of "."
notation so it never matched) and adds a node_modules exclude as a
safety net.

* fix: use precise node_modules exclude patterns

Use "*.node_modules" and "*.node_modules.*" instead of "*.node_modules*"
to avoid accidentally excluding valid packages that might contain
"node_modules" as a substring in their name.

pyproject.toml

@@ -58,7 +58,8 @@ studio = [
 ]
 
 [tool.setuptools.packages.find]
-exclude = ["images*", "tests*", "kernels/moe*"]
+include = ["unsloth*", "unsloth_cli*", "studio", "studio.backend*"]
+exclude = ["images*", "tests*", "*.node_modules", "*.node_modules.*"]
 
 [project.optional-dependencies]
 triton = [