Add a CreatedBy column to the Reports table and a canEdit() method on
the Report class so $report->canEdit() (already called from
web/ajax/reports.php) resolves to a real check. canEdit() permits the
report owner (CreatedBy == user) or any user/role with System=Edit.
Wire actions/report.php to stamp CreatedBy on first save and refuse
save/delete on existing reports the current user cannot edit.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>