config(default-grants): zero out shipped Crystals/Rupees/Ether

Tutorial gifts now cover the starter pack + starter deck flow (crystals
+ ether + tickets granted via ViewerPresents on signup), so the 50k/50k/50k
default deposit was double-dipping. Zero the ShippedDefaults so a fresh
viewer's currency reflects exactly what they've earned.

Also update the two tests that asserted the old 50k baseline.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.UnitTests/Controllers/AchievementControllerTests.cs

@@ -100,7 +100,7 @@ public class AchievementControllerTests
         var grant = rewardList[0];
         Assert.That(grant.GetProperty("reward_type").GetInt32(), Is.EqualTo(9));
         // For currency grants, reward_num is the POST-STATE TOTAL (per project convention,
-        // matches /pack/open behavior). Default-seeded viewer has 50000 rupees → 50100 after grant.
+        // matches /pack/open behavior). Default-seeded viewer starts at 0 rupees → 100 after grant.
         Assert.That(grant.GetProperty("reward_num").GetInt32(), Is.GreaterThanOrEqualTo(100),
             "reward_num is post-state total for currencies, must be at least the granted amount");
     }