The former v2 branch has merged into main, making the old "main is frozen,
submit to v2" guidance backwards. Update all contributor-facing entry points
to the current model: main is the active v2 development line; v1 maintenance
fixes target the v1 branch.
- CLAUDE.md: add a v2 "Current state" callout and a branch-targeting
Operational Rule (the AI-facing context).
- gh-create-pr skill: route v1 maintenance PRs to base v1.
- PR template: replace the stale hidden comment with a visible branch
callout and add a branch checklist item.
- CONTRIBUTING.md / docs/guides/contributing.md: rewrite the branch strategy
section to the new model.
- docs/guides/branching-strategy.md: add a current-model note and fix the PR
target guideline.
