v0.20.1

Fixed

• Edit-boundary hook checks NotebookEdit, whose path arrives as
  tool_input.notebook_path. Before this, notebook edits outside the boundary were allowed. It
  also resolves . and .. before matching: src/x/../../docs/y is checked as docs/y,
  and a newline in the path can't cut the resolution short (#21).
• The AC convention now actually auto-loads (#22). Plugins have no rules component, so the
  plugin's ac-convention never loaded on its own. Onboard now always writes the project copy
  .claude/rules/ac-convention.md. If a copy exists whose paths: doesn't cover the artifact
  root, onboard rewrites that one line. Doctor checks the copy at every root: WARN on the
  default root (projects onboarded earlier: re-run /lcd:onboard), FAIL on a custom root as
  before. Coverage is judged on the paths: globs ("<root>/**"), so root docs no longer
  passes on the stock docs/lcd globs. Docs no longer claim the plugin copy auto-loads.
• Boundary-hook tests: the fixture's branch switch-back failed silently in a repo with no
  commits, so every later case ran with no active work-item and passed without testing anything.