Add contract management and invoice settings pages

- Created a new Blade view for managing brand contracts with forms for adding and editing contracts, including client and category selection.
- Implemented success message notifications for contract actions.
- Added a new Blade view for invoice settings, allowing customization of invoice number format, header branding, and default values for new invoices.
- Introduced a new PDF view for generating rate cards with customizable styles based on user profile settings.
- Developed a profile management page for rate cards, enabling users to update their identity, appearance, and visibility settings.

app/Models/InvoiceSettings.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class InvoiceSettings extends Model
+{
+    protected $table = 'invoice_settings';
+
+    protected $fillable = [
+        'invoice_prefix',
+        'invoice_next_number',
+        'header_name',
+        'header_title',
+        'header_logo',
+        'default_tax_rate',
+        'default_currency',
+        'default_service_description',
+        'default_bank_name',
+        'default_branch_name',
+        'default_bank_account',
+        'default_bank_holder',
+        'default_notes',
+    ];
+
+    protected $casts = [
+        'invoice_next_number' => 'integer',
+        'default_tax_rate'    => 'decimal:2',
+    ];
+
+    /** Always return the single settings row, creating it if absent. */
+    public static function instance(): self
+    {
+        return static::firstOrCreate([], [
+            'invoice_prefix'      => 'INV',
+            'invoice_next_number' => 1,
+            'default_tax_rate'    => 11,
+            'default_currency'    => 'IDR',
+        ]);
+    }
+
+    /** Generate the next invoice number and increment the counter. */
+    public static function generateNumber(): string
+    {
+        $settings = static::instance();
+        $prefix   = rtrim($settings->invoice_prefix, '-');
+        $number   = str_pad((string) $settings->invoice_next_number, 3, '0', STR_PAD_LEFT);
+        $settings->increment('invoice_next_number');
+        return $prefix . '-' . $number;
+    }
+}