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/extensions/deployment.md

@@ -0,0 +1,49 @@
+---
+title: Deployment
+sidebar_position: 7
+---
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+# Deployment
+
+Once an extension has been developed, the deployment process involves packaging and uploading it to the host application.
+
+Packaging is handled by the `superset-extensions bundle` command, which:
+
+1. Builds frontend assets using Webpack (with Module Federation configuration).
+2. Collects backend Python source files and all necessary resources.
+3. Generates a `manifest.json` with build-time metadata, including the contents of `extension.json` and references to built assets.
+4. Packages everything into a `.supx` file (a zip archive with a specific structure required by Superset).
+
+To deploy an extension, place the `.supx` file in the extensions directory configured via `EXTENSIONS_PATH` in your `superset_config.py`:
+
+``` python
+EXTENSIONS_PATH = "/path/to/extensions"
+```
+
+During application startup, Superset automatically discovers and loads all `.supx` files from this directory:
+
+1. Scans the configured directory for `.supx` files.
+2. Validates each file is a properly formatted zip archive.
+3. Extracts and validates the extension manifest and metadata.
+4. Loads the extension, making it available for use.
+
+This file-based approach simplifies deployment in containerized environments and enables version control of extensions alongside infrastructure configuration.