feat(stateful-templates): schema + dispatch guards + allow cron/queue on group (M5.1)

0062 adds `materialized_from` on triggers (a managed app-owned copy links back
to its group template; CASCADE). The scheduler + queue-consumer queries gain
`AND t.app_id IS NOT NULL` so a group-owned stateful TEMPLATE is never
dispatched directly — only the per-descendant materialized app rows are.
validate_bundle_for + manifest parse now allow cron/queue on a group (email
stays rejected pending its per-app inbound-secret handling in M5.5). The
materialization reconcile that expands templates into app rows lands in M5.2.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/manager-core/src/cron_scheduler.rs

@@ -119,7 +119,7 @@ async fn tick(pool: &PgPool, now: DateTime<Utc>) -> Result<usize, sqlx::Error> {
                 d.schedule, d.timezone, d.last_fired_at \
          FROM cron_trigger_details d \
          JOIN triggers t ON t.id = d.trigger_id \
-         WHERE t.enabled = TRUE \
+         WHERE t.enabled = TRUE AND t.app_id IS NOT NULL \
          FOR UPDATE OF d SKIP LOCKED",
     )
     .fetch_all(&mut *tx)