G2: bump engine (gene foundation), load genes + gene demo command

Engine pointer -> bc18db5: brings in the organism-agnostic gene
foundation (GeneDef, managed Genome, Phenotype trait computation) plus a
parallel MrGameEng.Net library the game does not use.

Game wiring: register the "Gene" def type and ship Mods/Core/Defs/
genes.json — a full gene set covering the plant phenotype dimensions
(environment optima/tolerances, vigor, lifecycle, reproduction) plus a
discrete morph gene, each declaring its trait effects as formulas. A
dev-console 'gene [seed]' command generates a genome from these defs,
prints its alleles, expressed values and computed traits, then breeds a
child — demonstrating the whole pipeline end to end. These genes seed
the G3 migration of plants onto traits.

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

src/LittleSim/Content/GameContent.cs

@@ -1,5 +1,6 @@
 using MrGameEng.Atlases;
 using MrGameEng.Core;
+using MrGameEng.Genetics;
 using MrGameEng.Mods;
 
 namespace LittleSim.Content;
@@ -56,6 +57,7 @@ public sealed class GameContent
 
         var defs = new DefDatabase();
         defs.RegisterType<TerrainDef>("Terrain");
+        defs.RegisterType<GeneDef>("Gene");
         defs.RegisterType<PlantDef>("Plant");
         defs.RegisterType<PawnDef>("Pawn");
         defs.RegisterType<WorldPresetDef>("WorldPreset");

src/LittleSim/Scenes/WorldScene.cs

@@ -11,6 +11,7 @@ using MrGameEng.Assets;
 using MrGameEng.Core;
 using MrGameEng.DevConsole;
 using MrGameEng.Formulas;
+using MrGameEng.Genetics;
 using MrGameEng.Graphics;
 using MrGameEng.Host;
 using MrGameEng.Input;
@@ -486,10 +487,57 @@ public sealed class WorldScene : Scene
                 }
             }
         );
+        console.Register(
+            "gene",
+            "gene [seed] — generate a genome from Gene defs, show alleles/traits and a bred child",
+            (c, args) => RunGeneDemo(c, content, args)
+        );
         console.Register(
             "menu",
             "menu — return to the main menu",
             (_, _) => Switch(new MainMenuScene())
         );
     }
+
+    // Демонстрация генной системы (фаза G2): из Gene-дефов генерируем геном, печатаем аллели,
+    // выраженные значения и признаки (вычисленные формулами), затем скрещиваем двух особей.
+    private static void RunGeneDemo(DevConsole console, GameContent content, string[] args)
+    {
+        var genes = content.Defs.All<GeneDef>();
+        if (genes.Count == 0)
+        {
+            console.WriteLine("no Gene defs loaded");
+            return;
+        }
+
+        var registry = genes.ToDictionary(g => g.DefName, g => g, StringComparer.Ordinal);
+        var seed = args.Length > 0 ? int.Parse(args[0]) : Random.Shared.Next();
+        var random = new Random(seed);
+
+        console.WriteLine($"genome from {genes.Count} genes, seed {seed}:");
+        var parentA = Genome.Generate(genes, random);
+        foreach (var gene in genes)
+        {
+            var allele = parentA[gene.DefName];
+            console.WriteLine(
+                $"  {gene.DefName}: [{allele.A:0.##}, {allele.B:0.##}] -> {parentA.Express(gene):0.###}"
+            );
+        }
+
+        console.WriteLine("traits:");
+        foreach (var (trait, value) in Phenotype.Compute(parentA, registry).OrderBy(t => t.Key))
+        {
+            console.WriteLine($"  {trait} = {value:0.###}");
+        }
+
+        var parentB = Genome.Generate(genes, random);
+        var child = Genome.Breed(parentA, parentB, registry, random);
+        var childTraits = Phenotype.Compute(child, registry);
+        console.WriteLine(
+            $"bred child: {child.Alleles.Count} genes, "
+                + $"vigor={childTraits.GetValueOrDefault("vigor"):0.###}, "
+                + $"lifespan={childTraits.GetValueOrDefault("lifespan"):0.#}, "
+                + $"variant={childTraits.GetValueOrDefault("variant"):0}"
+        );
+    }
 }