Hazard: destructible cover — carve-able rocks that genuinely block until broken

Phase 1.5 long-term #8, the LAST 1.5 item (design review wf_e14dd739-069:
both HIGHs + the distinct MEDs verified before the session limit ate the
duplicate verifiers; unverified leftovers reasoned-closed in the spec).

Cover = a BlightClutter ghost (Variant 4) with a baked Environment-layer
BoxCollider: the runtime ghost's collider joins BuildPhysicsWorld ->
blocks the player CC and the enemy sweep while alive, and the gap opens
the instant the entity dies. Both hit paths already break it (the
clutter chassis); 8 hits to carve.

Review folds:
- HIGH: the 07-07 anti-stuck nudge would phase enemies THROUGH cover
  after ~1.5s (it exists to prevent room soft-locks). The nudge is now
  COVER-AWARE: a SphereCast identifies the blocker; a live BlightClutter
  ghost suppresses the phase (no soft-lock possible - the blocker is
  destructible); static-geometry wedges still nudge.
- HIGH: yield==durability made tanky cover an economy faucet. Deposit
  is DECOUPLED from the decrement at both hit sites: ScrapPerHit=0 =
  breaks in Remaining hits, yields NOTHING; fractional POSITIVE yields
  still credit >=1 (the B1 immortal-sink test pinned this - zero means
  zero, positive floors to 1).
- MEDs: HitRadius 1.2 (visual core, not a shot-eating disc), NO cover
  in Boss rooms (no boss depenetration backstop), scatter keep-out >=7u
  from the room origin (player landing + portal), Variant=4 explicit
  (the clutter block's explosive reroll cannot leak).
- Old static layer removed: 8 WorldColliders_RoomCover colliders
  (subscene) + the RoomCover_Visuals root (Game.unity).

Verified live: 3 cover ghosts spawned with SOLID baked colliders;
BLOCK - NudgeUntilTick stayed 0 across 3.5s of forced zero-progress
(old code arms at 1.5s); DEPENETRATE - an enemy shoved inside a live
rock exited to 1.7u (backstop holds against ghost colliders); CARVE -
the rock died to the real sweep and the spot probed OPEN. 470/470
EditMode; console clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/_Project/Scripts/Server/Combat/EnemyAISystem.cs

@@ -630,8 +630,24 @@ namespace ProjectM.Server
                     nav.ValueRW.LastPos = npos;
                     if (st >= StuckUnstickTicks)
                     {
-                        nav.ValueRW.NudgeUntilTick = TickUtil.NonZero(now + NudgeBurstTicks);
-                        st = 0u;
+                        // COVER-AWARE (destructible-cover review wf_e14dd739-069 HIGH): if what blocks this enemy
+                        // is a LIVE cover GHOST (BlightClutter carrier), do NOT phase-nudge — cover must genuinely
+                        // hold until the player breaks it. No soft-lock is possible: the blocker is destructible,
+                        // and the counter stays primed so any OTHER wedge (static geometry) still nudges next check.
+                        bool blockedByCover = false;
+                        if (havePhysics)
+                        {
+                            float3 toTgt = nTarget - npos; toTgt.y = 0f;
+                            float tl = math.length(toTgt);
+                            if (tl > 1e-4f && physics.CollisionWorld.SphereCast(
+                                    npos, 0.35f, toTgt / tl, math.min(1.8f, tl), out var coverHit, envFilter))
+                                blockedByCover = SystemAPI.HasComponent<BlightClutter>(coverHit.Entity);
+                        }
+                        if (!blockedByCover)
+                        {
+                            nav.ValueRW.NudgeUntilTick = TickUtil.NonZero(now + NudgeBurstTicks);
+                            st = 0u;
+                        }
                     }
                     nav.ValueRW.StuckTicks = st;
                 }

Assets/_Project/Scripts/Server/Economy/ResourceHarvestSystem.cs

@@ -153,6 +153,11 @@ namespace ProjectM.Server
                 // A positive baked yield must always make progress: a raw (int) truncation of a sub-1.0 per-hit
                 // value would deposit 0 AND never decrement Remaining -> an immortal target that silently eats shots.
                 int amount = math.max(1, (int)tgtYieldPerHit[bestIdx]);
+                // DECOUPLED deposit (cover review wf_e14dd739-069): DESTRUCTIBLE COVER has ScrapPerHit=0 — it
+                // breaks in Remaining hits but yields NOTHING (durability must not be an economy faucet).
+                // Nodes/clutter (PerHit >= 1) keep deposit == decrement exactly as before.
+                // zero means ZERO (cover); any POSITIVE yield still credits >= 1 (the fractional-yield guard).
+                int deposit = tgtYieldPerHit[bestIdx] > 0f ? amount : 0;
                 byte yieldId = tgtYieldId[bestIdx];
 
                 // Route the yield into the HARVESTING player's PERSONAL inventory. The projectile carries the
@@ -162,8 +167,9 @@ namespace ProjectM.Server
                 if (m_GhostOwnerLookup.HasComponent(projEntity)
                     && playerByConn.TryGetValue(m_GhostOwnerLookup[projEntity].NetworkId, out var ownedPlayer))
                     harvester = ownedPlayer;
-                HarvestMath.DepositYield(yieldId, amount, tgtToLedger[bestIdx], harvester,
-                    m_InvLookup, ledger, true, haveDb, itemDb);
+                if (deposit > 0)
+                    HarvestMath.DepositYield(yieldId, deposit, tgtToLedger[bestIdx], harvester,
+                        m_InvLookup, ledger, true, haveDb, itemDb);
                 int rem = tgtRemaining[bestIdx] - amount;
                 tgtRemaining[bestIdx] = rem;
                 ecb.DestroyEntity(projEntity);

Assets/_Project/Scripts/Server/Economy/RoomFieldSystem.cs

@@ -128,6 +128,33 @@ namespace ProjectM.Server
                         }
                     }
 
+                    // DESTRUCTIBLE COVER (OPTIONAL singleton; review wf_e14dd739-069): never in Boss rooms (the boss
+                    // has no depenetration backstop) and never inside the origin keep-out ring (player landing +
+                    // portal). Variant stays the prefab's 4 — NEVER rerolled (the clutter block's explosive
+                    // reroll must not leak into this copy).
+                    if (plan.RoomType != RoomTypeId.Boss
+                        && SystemAPI.TryGetSingleton<CoverFieldSpawner>(out var cover)
+                        && cover.Prefab != Entity.Null)
+                    {
+                        var kBaked = SystemAPI.GetComponent<LocalTransform>(cover.Prefab);
+                        var krng = new Random(RunMapMath.Hash(run.RunSeed, (uint)run.CurrentNodeId, 0xC0Eu) | 1u);
+                        int kCount = math.clamp(cover.Count, 0, 6);
+                        const float KeepOutFromOrigin = 7f;
+                        for (int i = 0; i < kCount; i++)
+                        {
+                            float3 pos = origin;
+                            for (int attempt = 0; attempt < 8; attempt++)
+                            {
+                                pos = RoomLayoutMath.ScatterInShape(plan.ShapeId, origin, i, kCount, ref krng);
+                                if (math.distance(pos.xz, origin.xz) >= KeepOutFromOrigin) break;
+                            }
+                            if (math.distance(pos.xz, origin.xz) < KeepOutFromOrigin) continue; // unlucky draws: drop the piece
+                            var e = ecb.Instantiate(cover.Prefab);
+                            ecb.SetComponent(e, kBaked.WithPosition(pos));
+                            ecb.AddComponent(e, new RoomTag { Room = room });
+                        }
+                    }
+
                     rf.LastSpawnedRoomEpoch = run.RoomEpoch;
                     SystemAPI.SetComponent(spawnerEntity, rf);
                 }