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_sidebars/version-6.1.0-sidebars.json

@@ -0,0 +1,48 @@
+{
+  "AdminDocsSidebar": [
+    {
+      "type": "doc",
+      "label": "Overview",
+      "id": "index"
+    },
+    {
+      "type": "category",
+      "label": "Installation",
+      "collapsed": false,
+      "items": [
+        {
+          "type": "autogenerated",
+          "dirName": "installation"
+        }
+      ]
+    },
+    {
+      "type": "category",
+      "label": "Configuration",
+      "collapsed": true,
+      "items": [
+        {
+          "type": "autogenerated",
+          "dirName": "configuration"
+        }
+      ]
+    },
+    {
+      "type": "link",
+      "label": "Database Drivers",
+      "href": "/user-docs/databases/",
+      "description": "See User Docs for database connection guides"
+    },
+    {
+      "type": "category",
+      "label": "Security",
+      "collapsed": true,
+      "items": [
+        {
+          "type": "autogenerated",
+          "dirName": "security"
+        }
+      ]
+    }
+  ]
+}