drop the hive's push of the legacy core/meta repo

Nothing reads core/meta: builds come from internal/meta. Remove push_meta, ensure_meta_remote, meta_read_access, ensure_repo, the per-agent forge sync that only served them, and the git commit path in meta.rs; remove_permission_files now just deletes the seed files.

hive-c0re/src/workers/permissions_import.rs

@@ -222,7 +222,6 @@ async fn send_at(client: &async_nats::Client, hive: &str, meta: &Path) -> Result
                 "import: the controller took the meta repo's permissions"
             );
             crate::meta::remove_permission_files()
-                .await
                 .context("deleting the imported permission files")?;
             Ok(ImportOutcome::Imported)
         }