feat: add account linking and improve sales table

- Add many-to-many relationships between Sale/Expense and Account models
- Create pivot tables for account_sale and account_expense with migrations
- Implement account syncing during sale/expense creation and editing
- Add accounts_list attribute to display comma-separated account names
- Introduce SaleService with DTO for sale creation logic
- Simplify sales table columns to show branch, reference, date, and creator
- Calculate and store aggregated financial fields from transactions
- Make series field read-only instead of disabled in sale form

app/Filament/Resources/SaleResource/Pages/EditSale.php

@@ -36,6 +36,16 @@ class EditSale extends EditRecord
 
     public function getFormDataMutation(array $data): array
     {
+        $transactions = $data['transactions'] ?? [];
+
+        $data['gross_amount'] = collect($transactions)->sum(fn (array $transaction) => (float) ($transaction['gross_amount'] ?? 0));
+        $data['exempt'] = collect($transactions)->sum(fn (array $transaction) => (float) ($transaction['exempt'] ?? 0));
+        $data['vatable_amount'] = collect($transactions)->sum(fn (array $transaction) => (float) ($transaction['vatable_amount'] ?? 0));
+        $data['output_tax'] = collect($transactions)->sum(fn (array $transaction) => (float) ($transaction['output_tax'] ?? 0));
+        $data['payable_withholding_tax'] = collect($transactions)->sum(fn (array $transaction) => (float) ($transaction['payable_withholding_tax'] ?? 0));
+        $data['discount'] = collect($transactions)->sum(fn (array $transaction) => (float) ($transaction['discount'] ?? 0));
+        $data['net_amount'] = collect($transactions)->sum(fn (array $transaction) => (float) ($transaction['net_amount'] ?? 0));
+
         return Arr::except($data, ['client', 'transactions', 'with_discount']);
     }
 
@@ -71,6 +81,16 @@ class EditSale extends EditRecord
                     ]
                 )->thenReturn();
             }
+
+            $accountIds = collect($transactions)
+                ->pluck('account_id')
+                ->filter()
+                ->unique()
+                ->values()
+                ->all();
+
+            $record->accounts()->sync($accountIds);
+
             DB::commit();
         } catch (\Exception $exception) {
             DB::rollBack();