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/Scripts/Simulation/Combat/ZoneEnemyComponents.cs

@@ -0,0 +1,57 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Marker on a runtime-spawned EXPEDITION combat enemy (a Husk variant the server's ZoneEnemyDirectorSystem
+    /// instantiates in the expedition region). Distinguishes zone enemies from base-siege Husks for the single
+    /// teardown point in ExpeditionFieldSystem and for the per-epoch clear count. Zone enemies ALSO keep
+    /// <c>EnemyTag</c> + <c>RegionTag{Expedition}</c>, so Slice-1 readability/health-bars/telegraphs/damage and the
+    /// per-region AI target filter all work for them unchanged.
+    /// </summary>
+    public struct ZoneEnemyTag : IComponentData { }
+
+    /// <summary>
+    /// Baked config for the expedition zone-enemy director (one singleton in the gameplay subscene; the server-only
+    /// ZoneEnemyDirectorSystem reads it). One epoch-seeded wave per sortie: a <see cref="GruntsPerWave"/> +
+    /// <see cref="ChargersPerWave"/> baseline that shifts grunt-&gt;charger as the expedition epoch climbs (the
+    /// highest-leverage variety lever), spawned one every <see cref="SpawnIntervalTicks"/> at a deterministic ring of
+    /// <see cref="RingSlots"/> slots / <see cref="RingRadius"/> around the expedition origin, capped at
+    /// <see cref="MaxAlive"/> concurrent (the v1 ghost-relevancy mitigation). On a real clear the returning player
+    /// banks <see cref="RewardOre"/> to the shared ledger, once per epoch.
+    /// </summary>
+    public struct ZoneEnemyDirector : IComponentData
+    {
+        public int MaxAlive;
+        public float RingRadius;
+        public int RingSlots;
+        public int SpawnIntervalTicks;
+        public int GruntsPerWave;
+        public int ChargersPerWave;
+        public int RewardOre;
+    }
+
+    /// <summary>
+    /// Baked pool of zone-enemy prefab variants the director draws from by composition. Index 0 = Grunt variant,
+    /// index 1 = Charger variant (see <see cref="ZoneEnemyMath.IsChargerSlot"/>). Aliases the existing Husk ghost
+    /// prefabs so zone enemies reuse the whole combat/readability stack with no new ghost type.
+    /// </summary>
+    public struct ZoneEnemyPrefab : IBufferElementData
+    {
+        public Entity Prefab;
+    }
+
+    /// <summary>
+    /// Runtime state of the zone-enemy director (server-only singleton; NOT replicated). Tracks its OWN spawn
+    /// counter (never WaveState.SpawnCounter), how many enemies remain to spawn for the current epoch's wave, the
+    /// next spawn tick, and the epoch the current wave was seeded for (re-syncs when CycleRuntime.ExpeditionEpoch
+    /// bumps). All session-scoped: 0-defaults safely on load (no SaveData field — DR-040 defers SaveData v6).
+    /// </summary>
+    public struct ZoneEnemyState : IComponentData
+    {
+        public uint SpawnCounter;
+        public int RemainingToSpawn;
+        public uint NextSpawnTick;
+        public int SeededEpoch;
+    }
+}