config: ship CLARIN-DSpace as the dtq-dev REST version prefix

dtq-dev is the UFAL/CLARIN customer base (see the ufal entry in the
customer registry), not a vendor-neutral integration branch. #985 set the
CLARIN identity on the REST root and the #1031 7.6.5 upgrade merge dropped
it; leaving dspace.version.prefix commented out would have left that
regression open, since the code default is "DSpace".

Activate the property here instead. The code default stays "DSpace", so the
fork identity now lives in configuration rather than in a literal that an
upgrade merge can silently revert. Non-CLARIN deployments set the property
to "DSpace".

Requested in review by milanmajchrak on #1405.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: jr-rk

dspace/config/dspace.cfg

@@ -43,9 +43,10 @@ dspace.name = DSpace at My University
 dspace.shortname = DSpace
 
 # Prefix for the version string exposed at the REST root (/server/api), rendered by the UI as
-# the HTML <meta name="Generator"> value. Defaults to "DSpace" when unset; CLARIN/customer
-# deployments may set e.g. "CLARIN-DSpace".
-# dspace.version.prefix = DSpace
+# the HTML <meta name="Generator"> value. Falls back to "DSpace" when unset or blank.
+# This branch is the UFAL/CLARIN base, so it ships the CLARIN identity by default.
+# Non-CLARIN deployments must set this to "DSpace".
+dspace.version.prefix = CLARIN-DSpace
 
 # Assetstore configurations have moved to config/modules/assetstore.cfg
 # and config/spring/api/bitstore.xml.