chore: rename plugin to headlamp-rook-plugin

Renames the plugin from headlamp-rook-ceph-plugin to headlamp-rook-plugin
across all files: package.json, package-lock.json, artifacthub-pkg.yml,
release workflow, README, CHANGELOG, CLAUDE.md, CONTRIBUTING, SECURITY,
and src/index.tsx.

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>

CLAUDE.md

@@ -6,7 +6,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 Headlamp plugin for Rook-Ceph cluster visibility.
 
-- **Plugin name**: `headlamp-rook-ceph-plugin`
+- **Plugin name**: `headlamp-rook-plugin`
 - **Rook-Ceph API group**: `ceph.rook.io/v1`
 - **Default namespace**: `rook-ceph`
 - **Reference plugin**: `../headlamp-tns-csi-plugin`