docs: cut 6.1.0 versions for docs, admin_docs, developer_docs, components

- Snapshot all four versioned docs sections at v6.1.0; master continues to
  serve as "Next" (lastVersion: current, banner: unreleased) so editing
  master keeps updating the canonical URLs
- Enable the previously-disabled components plugin and version it
- Rename stale "developer_portal" references to "developer_docs" across
  package.json scripts, manage-versions.mjs, theme files (DocVersionBadge,
  DocVersionBanner), DOCS_CLAUDE.md, and README.md (URL backward-compat
  redirect /developer_portal/* preserved)
- Add admin_docs version scripts; drop dead "tutorials" plugin id from
  the version badge
- Generalize fixVersionedImports in manage-versions.mjs to walk every
  section's snapshot and rewrite ../../src/ and ../../data/ imports,
  catching admin_docs and components files that previous version cuts
  would have broken
- Remove orphan files: developer_portal_versions.json,
  tutorials_versions.json, and stray empty versions.json files inside
  components/ and developer_docs/ content directories

docs/admin_docs_versioned_docs/version-6.1.0/index.md

@@ -0,0 +1,42 @@
+---
+title: Admin Documentation
+description: Administrator guides for installing, configuring, and managing Apache Superset
+---
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+# Admin Documentation
+
+This section contains documentation for system administrators and operators who deploy and manage Apache Superset installations.
+
+## What's in this section
+
+- **[Installation](/admin-docs/installation/installation-methods)** - Deploy Superset using Docker, Kubernetes, or PyPI
+- **[Configuration](/admin-docs/configuration/configuring-superset)** - Configure authentication, caching, feature flags, and more
+- **[Security](/admin-docs/security/)** - Set up roles, permissions, and secure your deployment
+
+## Related
+
+- **[Database Drivers](/user-docs/databases/)** - See User Docs for database connection setup (admins may need to install drivers)
+
+## Looking for something else?
+
+- **[User Documentation](/user-docs/)** - Guides for analysts and business users
+- **[Developer Documentation](/developer-docs)** - Contributing, extensions, and development guides