feat: separate trails and formations in cms

server/migrations/010_learning_path_kind.sql

@@ -0,0 +1,8 @@
+-- Both content types are intentionally composed from existing courses. The
+-- distinction is editorial: a "trilha" is a guided sequence and a
+-- "formação" is a broader curriculum collection.
+alter table learning_paths
+  add column kind text not null default 'trail'
+  check (kind in ('trail', 'formation'));
+
+create index learning_paths_kind_index on learning_paths (kind, published_at desc);