The issue form only applies labels for web-form submissions; contributors
filing via API/CLI or from a fork lack the triage/write needed to set
labels, so their proposals landed unlabeled and never auto-added to the
Silo v1 project. Add an issues:opened workflow that stamps v1-proposed on
any [v1]-titled issue via the repo GITHUB_TOKEN, regardless of filer
permission.
Also drop epic from the proposal template's auto-labels: a fresh proposal
is a candidate, not yet a tracked epic. epic-ness (better: the Epic issue
type) is applied at acceptance/lock alongside v1 + milestone.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>