feat: add SocialAccount model, migration, and factory

Implement SocialAccount model with enum fields for network and type,
along with migration and factory. Includes NETWORKS and TYPES constants
for dropdown usage in Livewire forms and validation.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

database/factories/SocialAccountFactory.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\SocialAccount;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class SocialAccountFactory extends Factory
+{
+    protected $model = SocialAccount::class;
+
+    public function definition(): array
+    {
+        return [
+            'network' => fake()->randomElement(SocialAccount::NETWORKS),
+            'username' => fake()->userName(),
+            'email' => fake()->safeEmail(),
+            'password' => fake()->password(),
+            'type' => fake()->optional()->randomElement(SocialAccount::TYPES),
+        ];
+    }
+}