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/uploadpostschema.Schema.json

@@ -0,0 +1 @@
+{"schema":{"properties":{"already_exists":{"default":"fail","description":"What to do if the table already exists accepts: fail, replace, append","enum":["fail","replace","append"],"type":"string"},"column_data_types":{"description":"[CSV only] A dictionary with column names and their data types if you need to change the defaults. Example: {'user_id':'int'}. Check Python Pandas library for supported data types","type":"string"},"column_dates":{"description":"[CSV and Excel only] A list of column names that should be parsed as dates. Example: date,timestamp","items":{"type":"string"},"type":"array"},"columns_read":{"description":"A List of the column names that should be read","items":{"type":"string"},"type":"array"},"dataframe_index":{"description":"Write dataframe index as a column.","type":"boolean"},"day_first":{"description":"[CSV only] DD/MM format dates, international and European format","type":"boolean"},"decimal_character":{"description":"[CSV and Excel only] Character to recognize as decimal point. Default is '.'","type":"string"},"delimiter":{"description":"[CSV only] The character used to separate values in the CSV file (e.g., a comma, semicolon, or tab).","type":"string"},"file":{"description":"The file to upload","format":"text/csv","type":"string"},"header_row":{"description":"[CSV and Excel only] Row containing the headers to use as column names (0 is first line of data). Leave empty if there is no header row.","type":"integer"},"index_column":{"description":"[CSV and Excel only] Column to use as the row labels of the dataframe. Leave empty if no index column","type":"string"},"index_label":{"description":"Index label for index column.","type":"string"},"null_values":{"description":"[CSV and Excel only] A list of strings that should be treated as null. Examples: '' for empty strings, 'None', 'N/A', Warning: Hive database supports only a single value","items":{"type":"string"},"type":"array"},"rows_to_read":{"description":"[CSV and Excel only] Number of rows to read from the file. If None, reads all rows.","minimum":1,"nullable":true,"type":"integer"},"schema":{"description":"The schema to upload the data file to.","type":"string"},"sheet_name":{"description":"[Excel only]] Strings used for sheet names (default is the first sheet).","type":"string"},"skip_blank_lines":{"description":"[CSV only] Skip blank lines in the CSV file.","type":"boolean"},"skip_initial_space":{"description":"[CSV only] Skip spaces after delimiter.","type":"boolean"},"skip_rows":{"description":"[CSV and Excel only] Number of rows to skip at start of file.","type":"integer"},"table_name":{"description":"The name of the table to be created/appended","maxLength":10000,"minLength":1,"type":"string"},"type":{"description":"File type to upload","enum":["csv","excel","columnar"]}},"required":["file","table_name","type"],"type":"object","title":"UploadPostSchema"},"schemaType":"response"}