feat: Enhance reservation functionality

supabase/migrations/20260421000000_reservation_cancel_and_edit.sql

@@ -0,0 +1,22 @@
+-- Allow members to cancel their own reservations and edit reason/comment.
+
+-- 1. Expand status check constraint to include 'cancelled'
+alter table public.reservations
+  drop constraint reservations_status_check;
+
+alter table public.reservations
+  add constraint reservations_status_check
+  check (status in ('pending', 'tentative', 'confirmed', 'cancelled'));
+
+-- 2. Exclude cancelled reservations from the public slots view so cancelled
+--    slots appear as available again on the schedule.
+drop view if exists public.reservation_slots;
+
+create view public.reservation_slots
+  with (security_invoker = false)
+as
+  select id, boat_id, start_time, end_time, status
+  from public.reservations
+  where status <> 'cancelled';
+
+grant select on public.reservation_slots to authenticated;