feat(invoices): add billingEntityType/Id for polymorphic billing

src/lib/db/schema/financial.ts

@@ -15,7 +15,9 @@ import { files } from './documents';
 export const expenses = pgTable(
   'expenses',
   {
-    id: text('id').primaryKey().$defaultFn(() => crypto.randomUUID()),
+    id: text('id')
+      .primaryKey()
+      .$defaultFn(() => crypto.randomUUID()),
     portId: text('port_id')
       .notNull()
       .references(() => ports.id),
@@ -49,12 +51,16 @@ export const expenses = pgTable(
 export const invoices = pgTable(
   'invoices',
   {
-    id: text('id').primaryKey().$defaultFn(() => crypto.randomUUID()),
+    id: text('id')
+      .primaryKey()
+      .$defaultFn(() => crypto.randomUUID()),
     portId: text('port_id')
       .notNull()
       .references(() => ports.id),
     invoiceNumber: text('invoice_number').notNull(), // INV-YYYYMM-### auto-generated
     clientName: text('client_name').notNull(),
+    billingEntityType: text('billing_entity_type').notNull().default('client'), // 'client' | 'company'
+    billingEntityId: text('billing_entity_id').notNull().default(''),
     billingEmail: text('billing_email'),
     billingAddress: text('billing_address'),
     dueDate: date('due_date').notNull(),
@@ -82,13 +88,20 @@ export const invoices = pgTable(
     uniqueIndex('idx_invoices_number').on(table.portId, table.invoiceNumber),
     index('idx_invoices_port').on(table.portId),
     index('idx_invoices_status').on(table.portId, table.status),
+    index('idx_invoices_billing_entity').on(
+      table.portId,
+      table.billingEntityType,
+      table.billingEntityId,
+    ),
   ],
 );
 
 export const invoiceLineItems = pgTable(
   'invoice_line_items',
   {
-    id: text('id').primaryKey().$defaultFn(() => crypto.randomUUID()),
+    id: text('id')
+      .primaryKey()
+      .$defaultFn(() => crypto.randomUUID()),
     invoiceId: text('invoice_id')
       .notNull()
       .references(() => invoices.id, { onDelete: 'cascade' }),