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

Snapshots all four versioned Docusaurus sections at v6.1.0. Built on
top of the version-cutting tooling work in chore/docs-cut-6.1.0-versions
so the snapshot benefits from:

- Auto-gen refresh before snapshotting (database pages from engine
  spec metadata, API reference from openapi.json, component pages
  from Storybook stories) — captured at the SHA we cut from rather
  than whatever happened to be on disk.
- Data-import freeze: country list, feature flag table, database
  diagnostics, and component metadata are copied into snapshot-local
  `_versioned_data/` dirs so the historical version doesn't silently
  mutate when the source files change.
- Depth-aware import-path rewriter that handles deeply-nested
  component MDX files referencing `../../../src/` from the snapshot.

Versioning behavior: `lastVersion` stays at `current` for every
section, so the canonical URLs (`/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. The plugin block in docusaurus.config.ts
was already gated only by the `disabled` flag, so no other code
changes were needed to bring it back online.

The frozen `databases.json` in the snapshot is the canonical 80-database
artifact from the latest committed state in master (preserved by the
generator's input-hash cache), not a fallback regenerated from a
local Flask environment.

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

@@ -0,0 +1,66 @@
+---
+id: create-a-css-template
+title: "Create a CSS template"
+description: "Create a CSS template"
+sidebar_label: "Create a CSS template"
+hide_title: true
+hide_table_of_contents: true
+api: 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
+sidebar_class_name: "post 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={"Create a CSS template"}
+>
+</Heading>
+
+<MethodEndpoint
+  method={"post"}
+  path={"/api/v1/css_template/"}
+  context={"endpoint"}
+>
+
+</MethodEndpoint>
+
+
+
+Create a CSS template
+
+<Heading
+  id={"request"}
+  as={"h2"}
+  className={"openapi-tabs__heading"}
+>
+  <Translate id="theme.openapi.request.title">Request</Translate>
+</Heading>
+
+<ParamsDetails>
+
+</ParamsDetails>
+
+<RequestSchema
+  {...require("./create-a-css-template.RequestSchema.json")}
+>
+
+</RequestSchema>
+
+<StatusCodes
+  {...require("./create-a-css-template.StatusCodes.json")}
+>
+
+</StatusCodes>