feat(abstract-utxo): ignore .cursor directory

Add .cursor/ to the gitignore file to prevent editor-specific files from
being tracked in version control.

Issue: BTC-2916

Co-authored-by: llm-git <llm-git@ttll.de>

Author: OttoAllmendinger

.gitignore

@@ -18,3 +18,4 @@ modules/**/pack-scoped/
 coverage
 /.direnv/
 .claude/
+.cursor/