feat: add HasFactory and factories for ApiLog, BrentPrice, PricePrediction

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

database/factories/PricePredictionFactory.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Enums\PredictionSource;
+use App\Enums\TrendDirection;
+use App\Models\PricePrediction;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/** @extends Factory<PricePrediction> */
+class PricePredictionFactory extends Factory
+{
+    public function definition(): array
+    {
+        return [
+            'predicted_for' => fake()->dateTimeBetween('-30 days')->format('Y-m-d'),
+            'source' => fake()->randomElement(PredictionSource::cases()),
+            'direction' => fake()->randomElement(TrendDirection::cases()),
+            'confidence' => fake()->numberBetween(40, 85),
+            'reasoning' => fake()->sentence(12),
+            'generated_at' => now(),
+        ];
+    }
+
+    public function llm(): static
+    {
+        return $this->state(['source' => PredictionSource::Llm]);
+    }
+
+    public function ewma(): static
+    {
+        return $this->state(['source' => PredictionSource::Ewma]);
+    }
+}