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/schemas/chartdatarestapi-put.schema.mdx

@@ -0,0 +1,31 @@
+---
+id: chartdatarestapi-put
+title: "ChartDataRestApi.put"
+description: ""
+sidebar_label: "ChartDataRestApi.put"
+hide_title: true
+hide_table_of_contents: true
+schema: true
+sample: {"cache_timeout":0,"certification_details":"string","certified_by":"string","dashboards":[0],"datasource_id":0,"datasource_type":"table","description":"string","external_url":"string","is_managed_externally":true,"owners":[0],"params":"string","query_context":"string","query_context_generation":true,"slice_name":"string","tags":[0],"uuid":"3fa85f64-5717-4562-b3fc-2c963f66afa6","viz_type":["bar","area","table"]}
+custom_edit_url: null
+---
+
+import Schema from "@theme/Schema";
+import Heading from "@theme/Heading";
+
+<Heading
+  as={"h1"}
+  className={"openapi__heading"}
+  children={"ChartDataRestApi.put"}
+>
+</Heading>
+
+
+
+
+
+<Schema
+  {...require("./chartdatarestapi-put.Schema.json")}
+>
+
+</Schema>