Boss gate: the exit gate fails closed; it opens only for a boss that spawned and then died

ZonePack.BossSpawned records the spawn, since a dead boss leaves no entity. RunGoal.ExitOpen requires it, so an exit zone
without a boss stays sealed, and ZoneGenerator logs that configuration by field and code.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Assets/Scripts/ServerShared/RunGoal.cs

@@ -11,9 +11,10 @@ public static class RunGoal
 
     public static bool BossAlive(Zone zone) => Boss(zone) != null;
 
-    // The exit gate is open in the galaxy's exit zone once that zone holds no living boss.
+    // The exit gate fails closed: it is open only in the galaxy's exit zone, once a boss was spawned there and no living
+    // boss remains. An exit zone that never got a boss stays sealed, so a missing boss can never read as a dead one.
     public static bool ExitOpen(Zone zone) =>
-        zone.Galaxy?.Exit != null && zone.GalaxyZone == zone.Galaxy.Exit && !BossAlive(zone);
+        zone.Galaxy?.Exit != null && zone.GalaxyZone == zone.Galaxy.Exit && zone.Pack.BossSpawned && !BossAlive(zone);
 
     // Where the exit gate sits: at the adjacency wormholes' radius (the zone's radius times the ratio), in the middle of
     // the widest angular gap between them, so it shares a point with none. A zone with no neighbours gets the +x axis.

Assets/Scripts/ServerShared/Zone.cs

@@ -182,6 +182,7 @@ public class Zone
             Orbits = Orbits.Keys.Select(key => new CultRecordRef<OrbitData>(key)).ToList(),
             Planets = Planets.Keys.Select(key => new CultRecordRef<BodyData>(key)).ToList(),
             Time = _time,
+            BossSpawned = Pack.BossSpawned,
             // Cut 2 (docs/mining-cut.md): drop entries that carry no live information -- healed (no damage) and
             // not currently broken -- so a save never accumulates wear rows for chunks nobody has touched since
             // they last respawned.

Assets/Scripts/ServerShared/ZoneData.cs

@@ -43,6 +43,11 @@ public class ZonePack
     // default instance.
     [JsonProperty("chunkWear"), Key(6)]
     public List<ChunkWearPack> ChunkWear;
+
+    // True once this zone's boss has been spawned. The dead boss leaves no entity, so this is the one fact that tells a
+    // slain boss from one that never existed; RunGoal.ExitOpen reads it. Written only by ZoneGenerator, carried by PackZone.
+    [JsonProperty("bossSpawned"), Key(7)]
+    public bool BossSpawned;
 }
 
 // Cut 2 (docs/mining-cut.md): one packed wear entry for one chunk. "Field" names the body that owns the chunk

Assets/Scripts/ServerShared/ZoneGenerator.cs

@@ -349,8 +349,12 @@ public static class ZoneGenerator
 	        }
 	        boss.Boss = true;
 	        pack.Entities.Add(boss);
+	        pack.BossSpawned = true;
         }
 
+        if (galaxyZone == galaxy.Exit && !pack.BossSpawned)
+	        itemManager.Log("Galaxy.Exit has no boss: Galaxy.BossZones does not map a boss faction to the exit zone, or its boss could not be generated (ZoneGenerator exit-without-boss). The exit gate stays sealed.");
+
         if (!ambient) return pack;
 
         var enemyCount = (int)(random.NextFloat() * factionPresence * 2) + baseStationCount;

tests/Aetheria.Shared.Tests/RunGoalTests.cs

@@ -164,6 +164,52 @@ public sealed partial class RunStartTests
         Assert.True(RunGoal.ExitOpen(exit));
     }
 
+    // The gate fails closed. The main galaxy puts its bosses on choke points, not at its exit, so its exit zone never gets
+    // one: the gate stays sealed on arrival and when every boss in the galaxy dies, because a boss that never existed is
+    // not a dead one.
+    [Fact]
+    public void Exit_sealed_where_no_boss_was_spawned_main_galaxy()
+    {
+        foreach (var seed in new uint[] { 1, 2, 3, 4, 5, 6, 7, 8 })
+        {
+            var galaxy = RunStart.Generate(new MainGalaxy(), Inputs(() => seed));
+            var exit = ZoneOf(galaxy, galaxy.Exit);
+            Assert.False(RunGoal.ExitOpen(exit), $"seed {seed}: the gate is open on arrival");
+            foreach (var boss in exit.Entities.Where(entity => entity.IsBoss).ToArray())
+                boss.HeatstrokeDeath.OnNext(Unit.Default);
+            Assert.False(RunGoal.ExitOpen(exit), $"seed {seed}: the gate is open with no boss spawned");
+        }
+    }
+
+    // The same for a demo exit whose boss could not be generated: the zone logs the gap by name and the gate stays sealed.
+    [Fact]
+    public void Exit_sealed_and_logged_when_the_boss_cannot_be_generated()
+    {
+        AddPirates();
+        var galaxy = DemoGalaxy(1);
+        galaxy.BossZones.Clear();
+        var log = new List<string>();
+        var pack = BossZonePack(galaxy, LoggingItems(log), galaxy.Exit);
+        Assert.False(pack.BossSpawned);
+        Assert.Contains(log, line => line.Contains("Galaxy.Exit") && line.Contains("exit-without-boss"));
+        var exit = new Zone(_items, _planetSettings, pack, galaxy.Exit, galaxy);
+        Assert.False(RunGoal.ExitOpen(exit));
+    }
+
+    // A boss killed before the save stays dead after it, and the gate stays open: the spawn fact travels with the zone.
+    [Fact]
+    public void Exit_open_after_save_of_a_slain_boss()
+    {
+        AddPirates();
+        var galaxy = DemoGalaxy(1);
+        var exit = ZoneOf(galaxy, galaxy.Exit);
+        Assert.Single(exit.Entities, entity => entity.IsBoss).HeatstrokeDeath.OnNext(Unit.Default);
+        var repacked = exit.PackZone();
+        Assert.True(repacked.BossSpawned);
+        Assert.DoesNotContain(repacked.Entities, entity => entity.Boss);
+        Assert.True(RunGoal.ExitOpen(new Zone(_items, _planetSettings, repacked, galaxy.Exit, galaxy)));
+    }
+
     // The gate shares no point with an adjacency wormhole: every one is farther from it than a ship's wormhole reach.
     [Fact]
     public void Exit_gate_shares_no_point_with_a_wormhole()