fix: address final review findings — nerve consume ordering, character init, seeder costs, dead column

- Consume nerve before energy in CrimeService so energy is never lost when nerve is insufficient
- Initialize nerve/max_nerve from config in CharacterController::store (same pattern as energy/health)
- Add nerve_cost to all CrimeSeeder entries proportional to difficulty (1-5 range)
- Remove nerve_regen_at from Character $fillable/$casts/@property — column exists but is not yet wired up

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

app/Http/Controllers/Game/CharacterController.php

@@ -74,6 +74,8 @@ class CharacterController extends Controller
             'max_energy' => config('game.energy.max', 100),
             'health' => config('game.health.start_amount', 100),
             'max_health' => config('game.health.max', 100),
+            'nerve' => config('game.nerve.start_amount', 100),
+            'max_nerve' => config('game.nerve.max', 100),
             'strength' => 5,
             'defense' => 5,
             'speed' => 5,