fix(justfile): pull build and twine into publish recipe ephemerally

nbdev-pypi shells out to `python -m build` and `twine upload`, so the
ephemeral env needs both available. Without them the recipe fails
mid-publish with "twine not found" after the build step succeeds.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hamelsmu

justfile

@@ -41,7 +41,7 @@ build:
 
 # Publish to PyPI (builds and uploads)
 publish:
-    uv run --with nbdev nbdev-pypi
+    uv run --with nbdev --with build --with twine nbdev-pypi
 
 # Full release: bump version, export, test, and publish
 release: