👷‍♀️ Follow the default branch rename to main

[alecgibson]

At the moment, our workflow only triggers on pushes and pull requests targeting master, and the coverage badge is pinned to ?branch=master.

Since the default branch is now main, those filters match nothing. CI doesn't fail on main; it simply never runs, and with no required checks that's easy to miss entirely.

This change points both triggers at main and updates the Coveralls badge. Note that it had to land after the rename rather than before: for a pull_request event GitHub reads the workflow file from the merge ref but matches branches against the base branch, so this very commit would have gone untested on a PR still targeting master.

The Test badge only moves to the current actions/workflows/test.yml/badge.svg form, without a ?branch= parameter: that form already tracks whatever the default branch is, so there's no reason to hard-code a name here and have to revisit it again. Coveralls is different, since its own idea of our default branch is separate from GitHub's and needs setting by hand, so that badge stays explicit.

workflow_dispatch's branches filter is dropped rather than renamed, since the event has no such key in the Actions schema and GitHub has always ignored it.

Finally, the coverallsapp/github-action@master pins are deliberately left untouched. That is not because master is still their default branch — it isn't, they moved to main some time ago — but because their master is an abandoned ref last touched in April 2023, and retargeting it at main here would silently pull in three years of unreviewed third-party changes. Pinning it to v2 or a SHA wants to be its own change, with its own testing.

🤖 Generated with Claude Code

Co-Authored-By: Claude noreply@anthropic.com

[coveralls]

Coverage is 92.725% — rename-default-branch into main. No base build found for main.