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

Snapshots all four versioned Docusaurus sections at v6.1.0, cut from
master after the version-cutting tooling (#39837), broken-internal-
links fix (#40102), and user_docs rename (#40171) all landed. With
the rename in place, all four sections now produce parallel-named
files at the docs/ root (no more bare `versioned_docs/` outlier).

Versioning behavior: lastVersion stays at current for every section,
so the canonical URLs (/user-docs/..., /admin-docs/...,
/developer-docs/..., /components/...) continue to render content
from master. The current version is consistently labeled "Next"
with an unreleased banner, and 6.1.0 is a historical pin accessible
only via its explicit version segment.

Component playground: previously disabled: true in versions-config.json,
now enabled and versioned.

Snapshot includes:
- All MDX content for the four sections.
- Auto-gen captured fresh: 74 database pages (engine spec metadata),
  ~1,800 API reference files (openapi.json), 59 component pages
  (Storybook stories).
- Data imports frozen at cut time into snapshot-local _versioned_data/
  dirs:
    user_docs_versioned_docs/version-6.1.0/_versioned_data/src/data/databases.json
      (canonical 80-database diagnostics from master, preserved by the
      generator's input-hash cache)
    admin_docs_versioned_docs/version-6.1.0/_versioned_data/data/countries.json
    admin_docs_versioned_docs/version-6.1.0/_versioned_data/static/feature-flags.json
    developer_docs_versioned_docs/version-6.1.0/_versioned_data/static/data/components.json
- Import paths in deeply-nested files rewritten so they still resolve
  from one directory deeper inside the snapshot.
- developer_docs/extensions/overview.md snapshot has the FIXED
  ./mcp.md form (from #40102), so the SPA-nav 404 isn't baked into
  the 6.1.0 version.

Verified via full yarn build: exit 0, no broken links surfaced by
onBrokenLinks: throw.

docs/developer_docs_versioned_docs/version-6.1.0/api/update-a-css-template.api.mdx

@@ -0,0 +1,68 @@
+---
+id: update-a-css-template
+title: "Update a CSS template"
+description: "Update a CSS template"
+sidebar_label: "Update a CSS template"
+hide_title: true
+hide_table_of_contents: true
+api: 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
+sidebar_class_name: "put 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={"Update a CSS template"}
+>
+</Heading>
+
+<MethodEndpoint
+  method={"put"}
+  path={"/api/v1/css_template/{pk}"}
+  context={"endpoint"}
+>
+
+</MethodEndpoint>
+
+
+
+Update a CSS template
+
+<Heading
+  id={"request"}
+  as={"h2"}
+  className={"openapi-tabs__heading"}
+>
+  <Translate id="theme.openapi.request.title">Request</Translate>
+</Heading>
+
+<ParamsDetails
+  {...require("./update-a-css-template.ParamsDetails.json")}
+>
+
+</ParamsDetails>
+
+<RequestSchema
+  {...require("./update-a-css-template.RequestSchema.json")}
+>
+
+</RequestSchema>
+
+<StatusCodes
+  {...require("./update-a-css-template.StatusCodes.json")}
+>
+
+</StatusCodes>