feat(stateful-templates): materialize cron+queue templates + hooks (M5.2-M5.4)

materialize::rematerialize_stateful_templates reconciles a group cron/queue
template into one app-owned copy per descendant (materialized_from = template),
via the all-apps app_chain CTE ⋈ group-owned stateful templates. A precise
create/delete diff preserves cron last_fired_at on unchanged copies; a queue
copy is skipped-with-warning when the app already fills that queue's consumer
slot (the one-consumer invariant). Called full-live at the route-rebuild
chokepoints: apply (single + tree), app create/delete (apps_api), group
reparent (groups_api) — AppsState/GroupsState gain a pool. Pinned by
tests/stateful_templates.rs (per-app copy, idempotent, new-app materializes,
reparent de-materializes).

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

crates/manager-core/src/lib.rs

@@ -70,6 +70,7 @@ pub mod kv_repo;
 pub mod kv_service;
 pub mod log_sink;
 pub mod login_rate_limit;
+pub mod materialize;
 pub mod migrations;
 pub mod module_source;
 pub mod outbox_event_emitter;