Fix file sharing load speed and move error; misc updates

- Remove recursive directory size calculations (single Seafile API call per list)
- Remove 'Used in this location' usage display
- Fix move using v2 per-type endpoints instead of broken batch endpoint
- Send entry type from frontend for correct move routing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

supabase/migrations/20260420154500_subcontractor_purchase_orders.sql

@@ -0,0 +1,52 @@
+alter table public.subcontractor_payments
+  add column if not exists po_number text,
+  add column if not exists project_id uuid references public.projects(id) on delete set null,
+  add column if not exists due_date date,
+  add column if not exists terms text default 'Net 15',
+  add column if not exists sent_at timestamptz,
+  add column if not exists approved_at timestamptz,
+  add column if not exists cancelled_at timestamptz;
+
+alter table public.subcontractor_payments
+  drop constraint if exists subcontractor_payments_status_check;
+
+update public.subcontractor_payments
+set status = 'ready_to_pay'
+where status = 'pending';
+
+alter table public.subcontractor_payments
+  add constraint subcontractor_payments_status_check
+  check (status in ('draft', 'sent', 'approved', 'ready_to_pay', 'paid', 'cancelled'));
+
+with numbered as (
+  select
+    id,
+    'PO-' || to_char(coalesce(created_at, now()), 'YYYY') || '-' || lpad((row_number() over (order by created_at, id))::text, 4, '0') as generated_po_number
+  from public.subcontractor_payments
+  where po_number is null
+)
+update public.subcontractor_payments sp
+set po_number = numbered.generated_po_number
+from numbered
+where sp.id = numbered.id;
+
+create unique index if not exists subcontractor_payments_po_number_key
+  on public.subcontractor_payments(po_number)
+  where po_number is not null;
+
+drop policy if exists "External reads own subcontractor purchase orders" on public.subcontractor_payments;
+create policy "External reads own subcontractor purchase orders" on public.subcontractor_payments
+  for select using (
+    get_my_role() = 'external'
+    and profile_id = auth.uid()
+  );
+
+drop policy if exists "External updates own subcontractor purchase orders" on public.subcontractor_payments;
+create policy "External updates own subcontractor purchase orders" on public.subcontractor_payments
+  for update using (
+    get_my_role() = 'external'
+    and profile_id = auth.uid()
+  ) with check (
+    get_my_role() = 'external'
+    and profile_id = auth.uid()
+  );