Status effects expire on their data duration; loot rolls never throw

A status effect added without an explicit duration started with no remaining
turns and the countdown skipped it, so it never expired. OnTurnEnd counted
down a second time, expired unlimited effects after one turn and removed
expired stacks by id; it is now a pure hook. The victory screen rolls loot
through LootEntry.Roll, so a loot table with MinCount > MaxCount no longer
throws half-way through the battle end, and its success-path diagnostics are
no longer logged as errors. Mod unit tests for the status effect lifetime.

tests/StatusEffectQueueTests.cs

@@ -0,0 +1,43 @@
+namespace Cthangover.Mods.TurnBattle.Tests
+{
+    using Cthangover.Core.Cards.StatusEffect;
+    using Cthangover.Core.Characters;
+    using Cthangover.Core.Mods.Testing;
+
+    /// <summary>
+    /// Lifetime of status effects: the countdown runs once per turn start, a
+    /// duration from the effect's data counts like an explicit one, and the
+    /// turn-end hook does not shorten an effect a second time.
+    /// </summary>
+    public class StatusEffectQueueTests
+    {
+        private const string Stun = "effect/physics/stun";
+
+        [ModTest("status/data_duration_expires")]
+        static void DataDurationExpires(ModTestContext ctx)
+        {
+            var queue = StatusEffectService.Of(new Character { ID = "status_test" });
+
+            ModAssert.True(queue.Add(Stun), "stun applied with its data duration");
+            queue.OnTurnStart();
+            queue.OnTurnStart();
+            ModAssert.True(queue.HasStun(), "stun still active after 2 of 3 turns");
+            queue.OnTurnStart();
+            ModAssert.False(queue.HasStun(), "stun expired after its 3 turns");
+        }
+
+        [ModTest("status/turn_end_does_not_shorten")]
+        static void TurnEndDoesNotShorten(ModTestContext ctx)
+        {
+            var queue = StatusEffectService.Of(new Character { ID = "status_test" });
+
+            queue.Add(Stun, 2);
+            queue.OnTurnEnd();
+            queue.OnTurnStart();
+            ModAssert.True(queue.HasStun(), "one turn of two left after a full turn");
+            queue.OnTurnEnd();
+            queue.OnTurnStart();
+            ModAssert.False(queue.HasStun(), "expired after two turns");
+        }
+    }
+}