feat(audit): full-history JSONL export in the actions menu

The menu so far only exported the current view (type + search
filter over the page 100-event window). A second action now fetches
the complete event history of the active project scope in one
EventLog call (the RPC has no cursor and no server-side cap) and
writes it as JSONL. Serialisation extracted to a top-level function
with unit tests; a stale comment advertising the never-shipped
"chain audit export" command now names "chain admin events --json".
Studio 0.73.0.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/l10n/app_localizations_en.dart

@@ -1225,6 +1225,12 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get auditExportAction => 'Export current view as JSONL …';
 
+  @override
+  String get auditExportAllAction => 'Export full log as JSONL …';
+
+  @override
+  String get auditExportAllNothing => 'The log is empty — nothing to export.';
+
   @override
   String get auditExportNothing =>
       'No events in the current view — nothing to export.';