Add cash management schema and immediate variance alerts

supabase/migrations/0029_my_active_shift.sql

@@ -0,0 +1,48 @@
+-- =====================================================================
+-- 0029_my_active_shift.sql
+--
+-- Shift Control needs visibility into both OPEN and DECLARED shifts so a
+-- cashier can declare, review the drawer, and still finalize after a
+-- refresh. Transaction entry keeps using my_open_shift so no sales can be
+-- posted once close has been declared.
+-- =====================================================================
+
+set search_path = app, public;
+
+create or replace function app.my_active_shift(p_shop uuid)
+returns table (
+  shift_id uuid,
+  till_id uuid,
+  opened_at timestamptz,
+  status app.shift_status,
+  opening_usd numeric,
+  opening_lbp numeric,
+  declared_at timestamptz,
+  declared_close_usd numeric,
+  declared_close_lbp numeric
+)
+language sql
+security definer
+set search_path = app, public
+stable
+as $$
+  select
+    id,
+    till_id,
+    opened_at,
+    status,
+    opening_usd,
+    opening_lbp,
+    declared_at,
+    declared_close_usd,
+    declared_close_lbp
+  from app.shifts
+  where shop_id = p_shop
+    and user_id = auth.uid()
+    and status <> 'closed'
+  order by opened_at desc
+  limit 1;
+$$;
+
+revoke all on function app.my_active_shift(uuid) from public;
+grant execute on function app.my_active_shift(uuid) to authenticated;