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/create-a-new-dataset.api.mdx

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