feat(routing): add user admin panel support

Adds the user administration route, associated server handlers, and frontend assets for managing user accounts.

lib/server/server.go

@@ -69,6 +69,7 @@ func Run(addr string) error {
 		AdminAlerts:         app.handleAdminAlerts,
 		AdminBoxes:          app.handleAdminBoxes,
 		AdminBoxesAction:    app.handleAdminBoxesAction,
+		AdminUsers:          app.handleAdminUsers,
 		AdminSettings:       app.handleAdminSettings,
 		AdminSettingsExport: app.handleAdminSettingsExport,
 		AdminSettingsSave:   app.handleAdminSettingsSave,