Update installed mirror path to python-project-workflow

what:
- Update DEFAULT_INSTALLED path in validate.py from python-best-practices to python-project-workflow

why:
The skill was renamed. The local Hermes mirror path should match the new
skill name. Also pull latest commits after remote URL update and git
clean to remove 18MB of stale untracked files.

Author: CodeSigils

scripts/validate.py

@@ -26,7 +26,7 @@
 ROOT = Path(os.environ.get("PBP_SKILL_ROOT", DEFAULT_ROOT)).resolve()
 SKILL = ROOT / "skill" / "SKILL.md"
 REF_DIR = ROOT / "skill" / "references"
-DEFAULT_INSTALLED = Path.home() / ".hermes" / "skills" / "software-development" / "python-best-practices"
+DEFAULT_INSTALLED = Path.home() / ".hermes" / "skills" / "software-development" / "python-project-workflow"
 INSTALLED = Path(os.environ.get("PBP_SKILL_INSTALLED", DEFAULT_INSTALLED)).resolve()
 REQUIRED_REFS = {
     "project-orientation.md",