docs: update all references from OCI registry to GitHub Pages Helm repo

Update CLAUDE.md, README.md, and workflows README to reference the new
GitHub Pages Helm repository at https://cpfarhood.github.io/devcontainer
instead of the old OCI registry at oci://ghcr.io/cpfarhood/charts.

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

.github/workflows/README.md

@@ -15,7 +15,7 @@ Use this for all version releases:
 - ✅ Updates chart version
 - ✅ Creates git tag
 - ✅ Builds Docker image with all proper tags
-- ✅ Publishes Helm chart to GHCR
+- ✅ Publishes Helm chart to GitHub Pages (`https://cpfarhood.github.io/devcontainer`)
 - ✅ Creates GitHub Release with changelog
 - ✅ No more `[skip ci]` blocking builds!