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/bulk-delete-themes.api.mdx

@@ -0,0 +1,68 @@
+---
+id: bulk-delete-themes
+title: "Bulk delete themes"
+description: "Bulk delete themes"
+sidebar_label: "Bulk delete themes"
+hide_title: true
+hide_table_of_contents: true
+api: eJzFVttu3DYQ/RVi0IcYlb22kQKGgjw4roMkNRKju24LWMaGK41XsilSIUcbbwX+ezGkVnvxFkj74idJFOfMOXMjO2iklTUSWgfpbQe50YSaIO1ANo2qckmV0aMHZzSvubzEWvJbRVg7fqFlg5BCpQnnaMEnqxVprVxCAlSR4u850rRAhYTTqnDTHsp7n0ClIYVvLVrer2XN27+Bv0vAomuMdhhcnR4f8+OHOTbWNGipitY1OifnuMHZka30HPyas5k9YE4sAp9k3SjcMlwb+AQKdLmtGnYNKUxKrNGJWaseRRTJIK+PT16W8I2WLZXGVn9jkYrzlkrU1PsXFr+1lcVin55Nw6jk9csq+WxI3JtWF6mYlBi4oyMshEVnWpujKAw6oQ0JfKoc7RM1YARFp6cvnZvGmpw/ZwoF54WWqfhDqqqI+UFrjd2n48K0qghSe4Teml398tI98lETWi2VcGgXaKOKVJxr0Wp8ajDnpIVFYfK8tf9SgO8lSTWEIAGHeWtZI0+ph+8E6e0dDwiSc55cfQPCXQJPh7kpcByoxaGmpJ5DCvnN71eQgJIzVOvPWD383VolDv8Sv15eXU4uRQYlUZOORsrkUpXGUXp2fHY2kk01WpyMiP2NMhBZlmkhDj+IDM77lgmxTsU7lBat+On84uJyPJ5Ovvx2+TkD8MnA6HpJpdEbnIaFgVVVN8bSqt5dpjO9moni7bB8FGfOK6YifpR6EneXKAu07m23IyCDVGTQi8hA/CxkzsU2JfOI2mf6INONrTS9WhE6ciSpdVOO/8Gmzk9yIcchuRtatxbXWTDasdxBovwuKxL3SHkZ5P0XcV1UWCOVpmA1Mbe70tPVRrGbRI7B11Ueu6h/EuR/jRaeHxyLN5lm6kbhkTLz3ZAcvAmn2XaJv1sfFoJi+SYQuUIK/SmSQCOphBS2BXLIQn/FCm8tR3RvYGDX7RX/FgUuUJmmRk19p4aERaCusYZMbpRPR6OOoXzacR36Z2gXrSNTryASWEhb8UBz/XAJMPxe4L1sFfU0IQHUbc2d23/yI/TvNv6HyeRaDDg+AWazjTfofUZuHEcQ/+NbhTBWfLxmENayDbI3VL192O09Z3A1hsZ5TFjaD6MOZqFK3htbS8b79OeEcxS2Qdr/hWGIBtE+YeOpxXuLrvy/IOH+dG+inC32bYPWIW3cwTaWuHbivsVJDImjWobTob+B7a3PLRfDKUH4RKNGyUozVCiiri/cW5BNxf5OmEdQkgDnOSbyFrpuJh3eWOU9L8drIBf1jqvhSIN1BLb9PuIyXBy5ClXL/0PXrUoyHBkJxKYPHqLBeZ5jGEIrq2cnJqMMjRlnCCTAN6SNGAzZ6V/YweoqrJcb8F0Xd8RBwi0VeYS5Cv7Oe/8P7HX75w==
+sidebar_class_name: "delete 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={"Bulk delete themes"}
+>
+</Heading>
+
+<MethodEndpoint
+  method={"delete"}
+  path={"/api/v1/theme/"}
+  context={"endpoint"}
+>
+
+</MethodEndpoint>
+
+
+
+Bulk delete themes
+
+<Heading
+  id={"request"}
+  as={"h2"}
+  className={"openapi-tabs__heading"}
+>
+  <Translate id="theme.openapi.request.title">Request</Translate>
+</Heading>
+
+<ParamsDetails
+  {...require("./bulk-delete-themes.ParamsDetails.json")}
+>
+
+</ParamsDetails>
+
+<RequestSchema
+  {...require("./bulk-delete-themes.RequestSchema.json")}
+>
+
+</RequestSchema>
+
+<StatusCodes
+  {...require("./bulk-delete-themes.StatusCodes.json")}
+>
+
+</StatusCodes>