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/developer_docs_versioned_docs/version-6.1.0/api/get-dashboards-thumbnail.api.mdx

@@ -0,0 +1,68 @@
+---
+id: get-dashboards-thumbnail
+title: "Get dashboard's thumbnail"
+description: "Computes async or get already computed dashboard thumbnail from cache."
+sidebar_label: "Get dashboard's thumbnail"
+hide_title: true
+hide_table_of_contents: true
+api: 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
+sidebar_class_name: "get api-method"
+info_path: developer-docs/api/superset
+custom_edit_url: null
+hide_send_button: true
+show_extensions: true
+---
+
+import MethodEndpoint from "@theme/ApiExplorer/MethodEndpoint";
+import ParamsDetails from "@theme/ParamsDetails";
+import RequestSchema from "@theme/RequestSchema";
+import StatusCodes from "@theme/StatusCodes";
+import OperationTabs from "@theme/OperationTabs";
+import TabItem from "@theme/TabItem";
+import Heading from "@theme/Heading";
+import Translate from "@docusaurus/Translate";
+
+<Heading
+  as={"h1"}
+  className={"openapi__heading"}
+  children={"Get dashboard's thumbnail"}
+>
+</Heading>
+
+<MethodEndpoint
+  method={"get"}
+  path={"/api/v1/dashboard/{pk}/thumbnail/{digest}/"}
+  context={"endpoint"}
+>
+
+</MethodEndpoint>
+
+
+
+Computes async or get already computed dashboard thumbnail from cache.
+
+<Heading
+  id={"request"}
+  as={"h2"}
+  className={"openapi-tabs__heading"}
+>
+  <Translate id="theme.openapi.request.title">Request</Translate>
+</Heading>
+
+<ParamsDetails
+  {...require("./get-dashboards-thumbnail.ParamsDetails.json")}
+>
+
+</ParamsDetails>
+
+<RequestSchema
+  {...require("./get-dashboards-thumbnail.RequestSchema.json")}
+>
+
+</RequestSchema>
+
+<StatusCodes
+  {...require("./get-dashboards-thumbnail.StatusCodes.json")}
+>
+
+</StatusCodes>