Slice 3: Expedition Combat Spine — epoch-seeded zone waves (DR-040)

Reactivate the dormant Expedition region as a procedural combat venue.
v1 loop: walk the gate -> fight an epoch-seeded enemy wave in the
expedition -> clear -> return -> flat Ore reward (once per epoch) ->
escalated retaliation base siege.

- New sim types: ZoneEnemyTag, ZoneEnemyDirector (+ ZoneEnemyPrefab
  buffer), ZoneEnemyState, ZoneEnemyMath (grunt->charger composition
  by epoch). ZoneEnemyDirectorSystem (server, Burst): drip-spawns the
  wave at a deterministic ring under a MaxAlive cap while a player is
  out and the base is Calm; marks ClearedThisEpoch on a real clear.
  [UpdateAfter(ExpeditionFieldSystem)] only (avoids a sort cycle).
- BLOCKER 1: EnemyAISystem region-filters target selection (player +
  structure snapshots gain parallel region lists; no base structures /
  no Core fallback for expedition husks).
- BLOCKER 3: WaveSystem, ThreatDirectorSystem timeout cull, and
  CyclePhaseSystem DefendCleared + Core-breach cull all count/cull
  RegionTag{Base} husks only (the breach cull was caught region-blind
  by the post-impl review: a base breach wiped the live expedition
  wave and spuriously paid the reward).
- BLOCKER 4: reward de-duped via CycleRuntime.LastRewardedEpoch +
  ClearedThisEpoch; ExpeditionGateSystem deposits RewardOre once/epoch.
- ExpeditionFieldSystem teardown also culls zone enemies + region-
  guards the clutter loop. Subscene wired with the director + roster.

368/368 EditMode green + clean netcode Play smoke. Docs: DR-040 ->
built, session log, CLAUDE.md cross-region tag-reaudit rule.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/_Project/Tests/EditMode/CyclePhaseSystemTests.cs

@@ -173,8 +173,9 @@ namespace ProjectM.Tests
                 ledger.Add(new StorageEntry { ItemId = 2, Count = 100 });
                 ledger.Add(new StorageEntry { ItemId = 4, Count = 40 });
                 MakeWaveState(em, waveNumber: 6, phase: WavePhase.Spawning, remainingToSpawn: 3);
-                em.CreateEntity(typeof(EnemyTag)); // two live husks the team failed to clear
-                em.CreateEntity(typeof(EnemyTag));
+                // two live BASE husks the team failed to clear (RegionTag defaults to Region 0 = Base)
+                em.CreateEntity(typeof(EnemyTag), typeof(RegionTag));
+                em.CreateEntity(typeof(EnemyTag), typeof(RegionTag));
 
                 group.Update();
 
@@ -193,6 +194,38 @@ namespace ProjectM.Tests
             }
         }
 
+        [Test]
+        public void Base_Overrun_Disperses_Base_Husks_But_Spares_Expedition_Husks()
+        {
+            // Slice 3 regression: a BASE Core breach must NOT wipe an in-progress EXPEDITION wave (both share
+            // EnemyTag but live in different regions). A region-blind cull would also spuriously trip the zone
+            // director's aliveZone==0 clear/reward edge on the player's return.
+            var (world, group) = MakeWorld("BaseOverrunSparesExpedition", serverTick: 200);
+            using (world)
+            {
+                var em = world.EntityManager;
+                var cycle = MakeCycle(em, CyclePhase.Siege, defendStartWave: 5);
+                em.AddComponentData(cycle, new GoalProgress { Charge = 3, Target = 10 });
+                em.AddComponentData(cycle, new CoreIntegrity { Current = 0, Max = 100, OverrunTick = 0 }); // breached
+                var ledger = em.AddBuffer<StorageEntry>(cycle);
+                ledger.Add(new StorageEntry { ItemId = 2, Count = 100 });
+                ledger.Add(new StorageEntry { ItemId = 4, Count = 40 });
+                MakeWaveState(em, waveNumber: 6, phase: WavePhase.Spawning, remainingToSpawn: 3);
+                em.CreateEntity(typeof(EnemyTag), typeof(RegionTag)); // BASE husk (RegionTag defaults to Region 0 = Base)
+                var exp = em.CreateEntity(typeof(EnemyTag), typeof(RegionTag));
+                em.SetComponentData(exp, new RegionTag { Region = RegionId.Expedition }); // a husk out on the expedition
+
+                group.Update();
+
+                Assert.IsTrue(em.Exists(exp), "the expedition husk survives a base Core breach.");
+                using var huskQ = em.CreateEntityQuery(typeof(EnemyTag));
+                Assert.AreEqual(1, huskQ.CalculateEntityCount(),
+                    "only the BASE husk is dispersed by the breach; the in-progress expedition wave is untouched.");
+                Assert.AreEqual(RegionId.Expedition, em.GetComponentData<RegionTag>(exp).Region,
+                    "the survivor is the expedition-region husk.");
+            }
+        }
+
         [Test]
         public void Overrun_Resolves_Once_Then_Stays_Calm_Without_Recharging()
         {