Derive package versions from Git

[rcaloras]

Summary

• derive development and release versions from Git tags with setuptools-scm
• generate package version metadata for installed Bashhub commands
• build release artifacts from the published tag with full Git history

Verification

• ruff check bashhub tests/test_bashhub.py
• pytest (114 passed, 1 skipped)
• bats tests/shell (18 passed)
• built wheel reports its Git-derived version