feat: add NerveService and nerve regen scheduled commands

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

app/Services/Game/NerveService.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Services\Game;
+
+use App\Models\Character;
+
+class NerveService
+{
+    public function consume(Character $character, int $amount): bool
+    {
+        if (!$character->canAct()) {
+            return false;
+        }
+
+        return $character->consumeNerve($amount);
+    }
+
+    public function regenerate(Character $character): void
+    {
+        $regenRate = config('game.nerve.regen_rate', 1);
+
+        if ($character->max_nerve <= 0) {
+            $character->max_nerve = config('game.nerve.max', 100);
+        }
+
+        $character->addNerve($regenRate);
+    }
+
+    public function refillAll(): int
+    {
+        return Character::where('nerve', '<', \DB::raw('max_nerve'))
+            ->where('status', 'active')
+            ->update(['nerve' => \DB::raw('max_nerve')]);
+    }
+}