Linked Records with Cascade

Add on_delete behavior to the reference fields in this plugin. 1. Find all reference fields in the plugin's record schemas. 2. For each reference field, determine the appropriate on_delete behavior: - If the child is "owned" by the parent (tasks on a project, line items on an invoice), set on_delete: :cascade so children are automatically deleted with the parent. - If the child requires the parent to exist (cannot be orphaned), set on_delete: :restrict so deletion is refused while children exist. - If the link is optional (contacts on a deal, tags on a post), keep on_delete: :nullify (the default) so the reference is cleared. 3. Update the reference field declarations in plugin.rb with the on_delete option: { key: 'project_id', type: :reference, target: 'projects', on_delete: :cascade } 4. Add a user-facing message in the parent's show page about what happens on delete. Only modify the files that need changes. Use patch_plugin_file for small edits.