feat: add fuel:archive command and monthly scheduler entry

Completes Tasks 12 + 13 from docs/superpowers/plans/2026-04-03-fuel-api-ingestion.md.

- ArchiveOldPricesCommand moves station_prices rows older than 12 months
  into station_prices_archive in chunks of 1000, wrapping each chunk's
  insert + delete in a DB::transaction so a partial failure can't
  duplicate rows.
- StationPriceArchive: add $table = 'station_prices_archive'; without it
  Eloquent infers 'station_price_archives' and the insert would fail.
- routes/console.php: register fuel:archive monthly on the 1st at 04:00
  UTC, alongside the other fuel/oil scheduler entries.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/Models/StationPriceArchive.php

@@ -10,15 +10,17 @@ use Illuminate\Database\Eloquent\Relations\BelongsTo;
 #[Fillable(['station_id', 'fuel_type', 'price_pence', 'price_effective_at', 'price_reported_at', 'recorded_at'])]
 class StationPriceArchive extends Model
 {
+    protected $table = 'station_prices_archive';
+
     public $timestamps = false;
 
     protected function casts(): array
     {
         return [
-            'fuel_type'          => FuelType::class,
+            'fuel_type' => FuelType::class,
             'price_effective_at' => 'datetime',
-            'price_reported_at'  => 'datetime',
-            'recorded_at'        => 'datetime',
+            'price_reported_at' => 'datetime',
+            'recorded_at' => 'datetime',
         ];
     }