Forum import: archived comments posted under their original author names

One account per original author (nickname = name as signed on the old
site, group 'Original site'), display-name driver 'museum' keeps the
brackets; --replace re-imports threads without real replies.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YDRjtmAiNpo5mK5N3d7QwZ

content/museum/magnavox-odyssey-100.md

@@ -54,7 +54,7 @@ params:
   - links
   - docs
   - comments
-  forum_thread: 6
+  forum_thread: 12
   photos:
   - title: ODYSSEY 100
     subtitle: ''