OpenAPI: default the file writer format to NXmxVDS, and regenerate

The schema declared NXmxLegacy while the server's own default has long been
NXmxVDS (FileWriterSettings.h), and the integration page added this release
tells users NXmxVDS is the one to use - legacy is the layout DIALS reads only
the first data file of. A generated client that fills in schema defaults was
therefore quietly asking for the layout we advise against.

The C++ server does not materialise the default at all - an absent enum reaches
Convert as INVALID_VALUE and throws - so this moves nothing server-side. It
moves the python and zod clients, which do fill defaults in, and the changelog
says so.

update_version.sh also picked up a grid-scan description that had been changed
on this branch but never regenerated into the clients ("mutually exclusive with
rotation_axis", which stopped being true when the two stopped being
alternatives).

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y5XisyYxmF8mUEQjzpMRe2

docs/python_client/docs/FileWriterSettings.md

@@ -6,7 +6,7 @@
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
 **overwrite** | **bool** | Inform jfjoch_write to overwrite existing files. Otherwise files would be saved with .h5.{timestamp}.tmp suffix.  | [optional] [default to False]
-**format** | [**FileWriterFormat**](FileWriterFormat.md) |  | [optional] [default to FileWriterFormat.NXMXLEGACY]
+**format** | [**FileWriterFormat**](FileWriterFormat.md) |  | [optional] [default to FileWriterFormat.NXMXVDS]
 
 ## Example
 

docs/python_client/docs/GridScan.md

@@ -1,6 +1,6 @@
 # GridScan
 
-Definition of a grid scan (mutually exclusive with `rotation_axis`)
+Definition of a grid scan. May be combined with a goniometer axis: a grid is often collected at a particular head position, and a stationary axis records where that was. 
 
 ## Properties