The Powered-by-BGG badge stays out of the repo

It's BGG's asset, provided through the owner's registered application
page — redistributing it in a public repo isn't ours to do. Each user
saves their own as data/powered-by-bgg.png (the export says so when
the file is absent), same principle as API tokens.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jXZFSTZQKzAC8fqpWSz9g

.gitignore

@@ -3,6 +3,8 @@
 *.storage_state.json
 data/.lan_key
 data/.own_repo
+# BGG's badge asset is licensed to YOUR registered app - get your own
+data/powered-by-bgg.png
 playwright/.auth/
 storage_state.json