fix: restore 'reformat' target as alias to fix CI

The self-test CI workflow expects 'make reformat' to exist.
Add it back as an alias alongside 'fix' and 'format'.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: dguido

{{cookiecutter.project_slug}}/Makefile

@@ -73,8 +73,8 @@ check: lint test
 typecheck ty: $(VENV)/pyvenv.cfg
 	uv run ty check src
 
-.PHONY: fix format
-fix format:
+.PHONY: fix format reformat
+fix format reformat:
 	uv run ruff format && \
 		uv run ruff check --fix