chore: track bd issues.jsonl and update .gitignore

Author: cv

.beads/.gitignore

@@ -36,3 +36,4 @@ beads.right.meta.json
 # contributors to accidentally commit upstream issue databases.
 # The JSONL files (issues.jsonl, interactions.jsonl) and config files
 # are tracked by git by default since no pattern above ignores them.
+last-touched