feat: user preview, bulk and record actions and the permanent delete

- the list opens the preview, which shows one status hint (banned,
  deactivated, not activated, suspended) and the IP address fields
- bulk actions activate, deactivate, restore, ban and unban; record
  actions activate, unban and unsuspend, offered while they apply
- delete (form button and bulk) removes the user for good with the
  throttle rows, group memberships and attachments in one transaction;
  blobs go after the commit
- a privileged-group member is still refused, a bulk delete as a whole

admin.go

@@ -12,7 +12,7 @@ import (
 // adminFS holds the admin YAML and partials, file by file: the controllers
 // directory also holds files that are not admin assets.
 //
-//go:embed controllers/users/config_list.yaml controllers/users/config_form.yaml controllers/users/config_filter.yaml models/user/fields.yaml models/user/columns.yaml
+//go:embed controllers/users/config_list.yaml controllers/users/config_form.yaml controllers/users/config_filter.yaml controllers/users/_hint.htm models/user/fields.yaml models/user/columns.yaml
 var adminFS embed.FS
 
 func (p *Plugin) AdminFS() fs.FS { return adminFS }