GitHook controller was generating a Deployment without any persistent
storage — only a ConfigMap volume at /config. The worker needs /data to
access repo storage paths (APP_REPOS_ROOT defaults to /data/repos).
Changes:
- GitHookSpec: added storage_size field (default 10Gi), matching the
pattern already used by GitServerSpec
- git_hook.rs reconcile(): now creates a PVC ({name}-data) before the
Deployment, mounts it at /data, and sets APP_REPOS_ROOT=/data/repos
- git-hook-crd.yaml: synced storageSize field into the CRD schema
