Run 11: satiation and quarry return - clean two-year stability

Granary satiation: hunger scars motivate storage only until town
capacity could carry a winter (pop x 45); sprawl of ~10 granaries falls
to the sated level. Quarry return: packs stuck with undroppable stone
after rebuilds made starving porters; unneeded stone goes back to the
quarry (matter conserved, packs unclogged).

Also corrects the record: run 10's zero-ruin year-2 claim came from
CSV contamination by orphaned headless child processes (console wrapper
kills didn't kill the tree). Clean verified result now: year-1
catastrophe and rebuild, then year-2 at 0.77 nourishment, zero new
ruins, 100% condition, textbook granary sawtooth.

Open in FINDINGS: accessible stone exhaustion plateaus housing below
population - a Phase 3 economy question (deeper quarrying, stockpiles).

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

scripts/World.cs

@@ -110,6 +110,21 @@ public class World
         return taken;
     }
 
+    /// <summary>Nearest node of a kind regardless of amount — for returning
+    /// unneeded minerals to the quarry rather than carrying them forever.</summary>
+    public ResourceNode? FindNearestAny(MaterialKind kind, Vector2 position)
+    {
+        ResourceNode? best = null;
+        float bestDist = float.MaxValue;
+        foreach (var node in Nodes)
+        {
+            if (node.Kind != kind) continue;
+            float d = position.DistanceSquaredTo(node.Cell);
+            if (d < bestDist) { best = node; bestDist = d; }
+        }
+        return best;
+    }
+
     /// <summary>
     /// Called once per in-game day by GameManager. Season multipliers throttle
     /// regeneration — winter is when the granary earns its clay.