006a T3: `dev.py claim` / `release` / `say` / `file` nf-v0au ← Beads

Twinned from https://github.com/cfsh/ninefold/issues/944 by tools/beads/import_github.py's reconcile pass.

From 006a-the-oracle-and-the-remaining-verbs.md's task table (design 006a). - Covers: 21; closes #677