feat: add Filament admin panel with migrations and design spec

- Add AdminPanelProvider mounting panel at `/admin` with `is_admin` auth guard
- Add `is_admin` boolean column to users table
- Add brent_prices and price_predictions tables with appropriate indexes
- Add comprehensive admin design spec covering resources, dashboard, navigation, and build order
- Configure default panel with amber primary color and standard middleware stack
- Add compiled Filament assets (actions.js, app.css)

app/Console/Commands/PredictOilPrices.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace App\Console\Commands;
+
+use App\Services\OilPriceService;
+use Illuminate\Console\Command;
+use Throwable;
+
+class PredictOilPrices extends Command
+{
+    protected $signature = 'oil:predict {--fetch : Fetch latest FRED prices before predicting}';
+
+    protected $description = 'Generate a Brent crude oil price direction prediction';
+
+    public function handle(OilPriceService $service): int
+    {
+        try {
+            if ($this->option('fetch')) {
+                $this->info('Fetching latest Brent crude prices from FRED...');
+                $service->fetchBrentPrices();
+            }
+
+            $this->info('Generating prediction...');
+            $prediction = $service->generatePrediction();
+
+            if ($prediction === null) {
+                $this->error('Could not generate a prediction — not enough price data.');
+
+                return self::FAILURE;
+            }
+
+            $this->info(sprintf(
+                'Done. [%s] direction=%s confidence=%d%% — %s',
+                strtoupper($prediction->source->value),
+                $prediction->direction->value,
+                $prediction->confidence,
+                $prediction->reasoning,
+            ));
+        } catch (Throwable $e) {
+            $this->error("Prediction failed: {$e->getMessage()}");
+
+            return self::FAILURE;
+        }
+
+        return self::SUCCESS;
+    }
+}