Add Stripe fee tracking on paid invoices + backfill function

- Store stripe_fee on invoices when webhook receives checkout.session.completed
- Display Stripe fee and net received in InvoiceDetail when paid via Stripe
- Add backfill-stripe-fees edge function to populate fee on existing paid invoices
- Migration: add stripe_fee column to invoices table
- Includes all pending portal changes (brand book, sign survey, task/project/company updates, etc.)

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

src/pages/client/MyInvoices.jsx

@@ -13,7 +13,7 @@ export default function MyInvoices() {
     async function load() {
       const { data } = await supabase
         .from('invoices')
-        .select('*, company:companies(name, email), items:invoice_items(*)')
+        .select('*, company:companies(name), items:invoice_items(*)')
         .order('created_at', { ascending: false });
       setInvoices((data || []).filter(inv => inv.status !== 'draft'));
       setLoading(false);