Release v0.2.0

What's new in 0.2.0

Features

• tilth cleanse — retire a finished, integrated session while keeping its audit record (c8ac18a)
• tilth push / tilth pr — push a session's branch to a remote / open a PR, plus
  post-run "working with this session" guidance (b355f6b)
  • tilth push / tilth pr — push a session's branch to a remote / open a PR, plus post-run "working with this session" guidance (b355f6b)

Docs

• Corrected the session-layout diagram and its alt text (60b637a)
• Explain why a worktree, not just a branch (5fdc253)
• README: editable-install path + uvx for testing the published release (8139597)