feat: add editable ordered trail pages

server/migrations/015_seed_trails_from_legacy_categories.sql

@@ -0,0 +1,20 @@
+-- Course categories were previously presented as trilhas but only stored a
+-- label. Turn every existing label into a real ordered trilha without moving
+-- or deleting any course.
+insert into learning_paths (title, description, status, published_at)
+select category.name, '', 'draft', null
+from course_categories category
+where not exists (
+  select 1 from learning_paths path where lower(path.title) = lower(category.name)
+);
+
+insert into learning_path_courses (learning_path_id, course_id, position)
+select path.id, course.id, ranked.position
+from (
+  select id, category, row_number() over (partition by category order by published_at nulls last, title, id)::integer as position
+  from courses
+  where status <> 'archived'
+) ranked
+join courses course on course.id = ranked.id
+join learning_paths path on lower(path.title) = lower(ranked.category)
+on conflict (learning_path_id, course_id) do nothing;

server/src/routes/manage-courses.ts

@@ -271,7 +271,18 @@ export const manageCourseRoutes: FastifyPluginAsync = async (app) => {
     const { courseId } = paramsSchema.parse(request.params);
     const accessError = await assertCanManageCourse(courseId, request.user);
     if (accessError) return reply.code(accessError.statusCode).send({ error: accessError.error });
-    await pool.query(`update courses set status = 'archived', published_at = null where id = $1`, [courseId]);
+    const client = await pool.connect();
+    try {
+      await client.query('begin');
+      await client.query(`update courses set status = 'archived', published_at = null where id = $1`, [courseId]);
+      await client.query('delete from learning_path_courses where course_id = $1', [courseId]);
+      await client.query('commit');
+    } catch (error) {
+      await client.query('rollback');
+      throw error;
+    } finally {
+      client.release();
+    }
     await recordAudit({ actorId: request.user.id, action: 'course.archived', subjectType: 'course', subjectId: courseId, ipAddress: request.ip });
     return reply.code(204).send();
   });