Soul layer: imprints, warmth echoes, and consequences

Ports the Unity POC soul systems into the sim:
- Warmth echoes: villagers remember who fed them (+0.15) and who turned
  them away (-0.25). Ask-for-food targeting runs on memory, not
  omniscience; the remembered-cold are not asked. Echoes fade daily.
- Refusing the hungry while holding food marks the refuser (others-regard
  debris) and is logged; empty-handed is not refusal.
- Harvesting below the 50% commons line marks the taker per unit taken.
- Soul-to-soul atmospheric pressure (SoulFieldSystem port): encased souls
  darken nearby atmospheres, clear souls lighten them.
- Debris costs biologically: nourishment drains faster and meals restore
  less as the soul encases.
- Instrumentation: avg_debris + refusals in daily stats; per-villager
  nourish/health/debris; refusals in the contact log; map dots dim with
  encasement.

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

scripts/TradeSystem.cs

@@ -13,6 +13,42 @@ public static class TradeSystem
     /// <summary>Trades since the last daily stats snapshot.</summary>
     public static int TradesToday;
 
+    /// <summary>Refusals since the last daily stats snapshot.</summary>
+    public static int RefusalsToday;
+
+    /// <summary>
+    /// A hungry villager asks another for food, face to face.
+    ///
+    /// Willingness comes from the soul (or from a warm history with this
+    /// particular person). Refusing the hungry while holding food is a
+    /// deliberate darkening of another — it marks the refuser's soul
+    /// (others-regard debris, per DESIGN.md) and leaves a cold echo in the
+    /// asker's memory. The world keeps score the only way it knows how.
+    /// </summary>
+    public static void RequestGift(Npc giver, Npc asker)
+    {
+        giver.Inventory.TryGetValue(MaterialKind.Food, out float giverFood);
+        bool hasFood = giverFood > 3f;
+        bool willing = giver.Soul.Generosity >= 0.3f || giver.GetWarmth(asker.Name) > 0.5f;
+
+        if (hasFood && willing)
+        {
+            Execute(giver, asker, MaterialKind.Food);
+            return;
+        }
+
+        if (hasFood && !willing)
+        {
+            // Refused with a full pack — the act that costs.
+            RefusalsToday++;
+            asker.RecordEcho(giver.Name, -0.25f);
+            giver.Imprint.OthersRegard = Godot.Mathf.Clamp(giver.Imprint.OthersRegard + 0.02f, 0f, 1f);
+            StatsLogger.LogRefusal(giver, asker);
+        }
+        // Empty-handed is not refusal: no debris, no echo. You cannot darken
+        // your soul with what you do not have.
+    }
+
     /// <summary>
     /// Need-based: the trigger is a person in need, not an inventory gap.
     /// Food flows to the hungry first; raw material surplus vs. genuine
@@ -52,6 +88,10 @@ public static class TradeSystem
 
         StatsLogger.LogGift(giver, receiver, material, given);
 
+        // Warmth lands on both sides — more on the one who was fed.
+        receiver.RecordEcho(giver.Name, +0.15f);
+        giver.RecordEcho(receiver.Name, +0.05f);
+
         // The kindness lands on both atmospheres — gently.
         giver.Imprint.ExternalPerception    -= 0.002f;
         receiver.Imprint.ExternalPerception -= 0.002f;