feat(cli): mred version update subcommand

`mred version update ID [--status open|closed] [--due YYYY-MM-DD]
[--name NAME]` flips milestone status, dates, and names; at least one
flag is required (usage error otherwise) and only provided flags are
sent. Text mode prints "updated version #N", -o json re-fetches and
emits the stored version, exit codes follow the 0/1/2 convention.

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

internal/cli/cli.go

@@ -31,6 +31,7 @@ Usage:
                     [--desc FILE|-] [--note TEXT] [-o json]
   mred version list -p PROJECT [-o json]
   mred version create -p PROJECT -n NAME [--due DATE] [--status open|closed] [-o json]
+  mred version update ID [--status open|closed] [--due DATE] [--name NAME] [-o json]
   mred category list -p PROJECT [-o json]
   mred category create -p PROJECT -n NAME [-o json]
   mred relation create FROM TO --type blocks|relates [-o json]