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-security-user-registrations.api.mdx

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