G1 add homework field to lessons API

database/migrations/20260724_g1_homework_field.sql

@@ -0,0 +1,14 @@
+-- G1: Homework as a first-class lesson/planner field.
+-- Apply to DEV Supabase only before promoting app/api changes.
+
+alter table if exists public.taught_lessons
+  add column if not exists homework text not null default '';
+
+alter table if exists public.planned_lessons
+  add column if not exists homework text not null default '';
+
+comment on column public.taught_lessons.homework is
+  'Teacher-authored homework for this taught lesson; surfaced in lesson/timetable views.';
+
+comment on column public.planned_lessons.homework is
+  'Default homework carried by a lesson plan and copied to a taught lesson when delivered.';