refactor(client): extract base account generation to command

Move the logic for generating base accounts for a new client from the ClientObserver into a dedicated command class (GenerateBaseAccountCommand). This improves code organization and reusability.

- The command is now used in the ClientObserver::created method.
- The command is also made available as a manual action in the AccountsRelationManager table header, allowing admins to generate base accounts for existing clients that lack them.
- Added necessary imports to the CreateSale page, though the command is not directly used there in this diff, suggesting preparatory work for future integration.

app/Commands/Clients/GenerateBaseAccountCommand.php

@@ -0,0 +1,64 @@
+<?php
+
+namespace App\Commands\Clients;
+
+use App\Commands\Command;
+use Illuminate\Support\Facades\DB;
+
+class GenerateBaseAccountCommand
+{
+    /**
+     * Create a new class instance.
+     */
+    public function __construct()
+    {
+        //
+    }
+
+    /**
+     * Execute the command.
+     */
+    public function execute($client): void
+    {
+        DB::transaction(function () use ($client) {
+            $client->accounts()->createMany([
+                [
+                    'account_type_id' => 1,
+                    'account' => 'Cash',
+                    'normal_balance' => 'debit',
+                ],
+                [
+                    'account_type_id' => 1,
+                    'account' => 'Input Tax',
+                    'normal_balance' => 'debit',
+                ],
+                [
+                    'account_type_id' => 1,
+                    'account' => 'Creditable Withholding Tax',
+                    'normal_balance' => 'debit',
+                ],
+                [
+                    'account_type_id' => 2,
+                    'account' => 'Output Tax',
+                    'normal_balance' => 'credit',
+                ],
+                [
+                    'account_type_id' => 2,
+                    'account' => 'Payable Withholding Tax',
+                    'normal_balance' => 'credit',
+                ],
+                [
+                    'account_type_id' => 5,
+                    'account' => 'Vat Exempt Revenue',
+                    'normal_balance' => 'credit',
+                ],
+                [
+                    'account_type_id' => 4,
+                    'account' => 'Sales Discount',
+                    'normal_balance' => 'debit',
+                ],
+            ]);
+        });
+    }
+
+}