docs(main): point CI badges at canonical workflow files (#212)

The badges referenced ci.yml on each version branch, but
shields.io's `github/actions/workflow/status` lookup operates against
the repository's default branch (main). On main there is no ci.yml —
the canonical workflows are ci-v2.yml / ci-v3.yml / ci-v4.yml. Each
version branch carries a thin shim called ci.yml that delegates to the
matching ci-vN.yml on main via workflow_call. shields.io cannot resolve
those shims, so all three badges showed "no status".

Fix: point each badge at its canonical ci-vN.yml on main. The workflow
itself only fires for runs originating from the matching version branch,
so the badge accurately reflects "v2 CI", "v3 CI", "v4 CI" status.

Click-through links updated to drop the now-redundant
`?query=branch%3AvN` filter.

Co-authored-by: claude-flow <ruv@ruv.net>

Author: pacphi

README.md

@@ -1,9 +1,9 @@
 # Sindri
 
 [![License](https://img.shields.io/github/license/pacphi/sindri)](LICENSE)
-[![v2 CI](https://img.shields.io/github/actions/workflow/status/pacphi/sindri/ci.yml?branch=v2&label=v2%3A%20CI)](https://github.com/pacphi/sindri/actions/workflows/ci.yml?query=branch%3Av2)
-[![v3 CI](https://img.shields.io/github/actions/workflow/status/pacphi/sindri/ci.yml?branch=v3&label=v3%3A%20CI)](https://github.com/pacphi/sindri/actions/workflows/ci.yml?query=branch%3Av3)
-[![v4 CI](https://img.shields.io/github/actions/workflow/status/pacphi/sindri/ci.yml?branch=v4&label=v4%3A%20CI)](https://github.com/pacphi/sindri/actions/workflows/ci.yml?query=branch%3Av4)
+[![v2 CI](https://img.shields.io/github/actions/workflow/status/pacphi/sindri/ci-v2.yml?branch=main&label=v2%3A%20CI)](https://github.com/pacphi/sindri/actions/workflows/ci-v2.yml)
+[![v3 CI](https://img.shields.io/github/actions/workflow/status/pacphi/sindri/ci-v3.yml?branch=main&label=v3%3A%20CI)](https://github.com/pacphi/sindri/actions/workflows/ci-v3.yml)
+[![v4 CI](https://img.shields.io/github/actions/workflow/status/pacphi/sindri/ci-v4.yml?branch=main&label=v4%3A%20CI)](https://github.com/pacphi/sindri/actions/workflows/ci-v4.yml)
 [![FAQ](https://img.shields.io/badge/FAQ-on%20fly.dev-blue)](https://sindri-faq.fly.dev)
 [![GHCR](https://img.shields.io/badge/GHCR-container%20registry-blue)](https://github.com/pacphi/sindri/pkgs/container/sindri)