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/get-the-csrf-token.api.mdx

@@ -0,0 +1,58 @@
+---
+id: get-the-csrf-token
+title: "Get the CSRF token"
+description: "Get the CSRF token"
+sidebar_label: "Get the CSRF token"
+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 the CSRF token"}
+>
+</Heading>
+
+<MethodEndpoint
+  method={"get"}
+  path={"/api/v1/security/csrf_token/"}
+  context={"endpoint"}
+>
+
+</MethodEndpoint>
+
+
+
+Get the CSRF token
+
+<ParamsDetails>
+
+</ParamsDetails>
+
+<RequestSchema
+  {...require("./get-the-csrf-token.RequestSchema.json")}
+>
+
+</RequestSchema>
+
+<StatusCodes
+  {...require("./get-the-csrf-token.StatusCodes.json")}
+>
+
+</StatusCodes>