fix(tasks): guard loop name length and surface loop ownership in the UI

Review follow-up:

- Reject loop files whose frontmatter name exceeds MAX_TASK_NAME_LENGTH
  (80): task names are clamped at storage time, so a raw name longer than
  the limit could never match the stored task identity. The file is treated
  as malformed (definition: null) instead of creating an unreachable
  definition; MAX_TASK_NAME_LENGTH is now exported from project-config.js
  and shared with loops.js.
- Surface loop-sourced tasks in the scheduled-tasks dialog: tasks carrying
  loopFile show a 'Managed by loop file <path>' note, and the enable
  toggle / edit / delete actions are disabled with an explanatory tooltip,
  since the file remains authoritative and would revert any such change.
  run-now stays available. New locale keys added to all 11 message files
  (i18n parity test enforces exact key sets).
- ScheduledTask type gains an optional loopFile field (additive, unknown
  to older clients).

packages/ui/src/lib/i18n/messages/es.ts

@@ -269,6 +269,9 @@ export const dict: Record<I18nKey, string> = {
   "sessions.scheduledTasks.dialog.taskToggle.pauseAria": "Pausar {taskName}",
   "sessions.scheduledTasks.dialog.taskToggle.enabled": "Habilitado",
   "sessions.scheduledTasks.dialog.taskToggle.paused": "Pausado",
+  'sessions.scheduledTasks.dialog.loopFile.note': 'Gestionada por el archivo de bucle {file}',
+  'sessions.scheduledTasks.dialog.loopFile.toggleDisabled': 'La activación la controla el archivo de bucle; establece enabled en el frontmatter de Markdown',
+  'sessions.scheduledTasks.dialog.loopFile.actionsDisabled': 'Las tareas de bucle se configuran en su archivo Markdown .agents/loops',
   "sessions.scheduledTasks.editor.title.edit": "Editar tarea programada",
   "sessions.scheduledTasks.editor.title.new": "Nueva tarea programada",
   "sessions.scheduledTasks.editor.description": "Configura una tarea del lado del servidor que crea una nueva sesión y envía un prompt.",