Dependabot Stack

Turns the week's open Dependabot PRs into one ordered stack of PRs (each based on the previous, via gh stack link), so they land as a single reviewable, mergeable chain instead of N independent PRs that will conflict on shared lockfiles.

Requires the gh-stack extension (gh extension install github/gh-stack if gh stack --help fails).

Step 0 — Establish repo and starting point

The target repo defaults to the current checkout. Only when $ARGUMENTS names a repo (owner/name) does that win: