G4: gene-driven content — fruiting, harvest products, leaf color

New plant content, all driven by genes through the trait layer (no engine
change — the genetics machinery already supports it).

- ProductDef + products.json (wood, grass, berries, acorn) — what plants
  yield; localized labels (ru/en).
- New numeric genes (genes.json): GeneFruitYield, GeneFruitSeason,
  GeneHarvestAmount, GeneLeafHue, each declaring its trait via formula.
  GenomeDef carries the per-species bases (PlantSet maps them into the
  species template); PlantDef gains harvestProduct / fruitProduct.
- PlantPhenotype gains FruitYield/FruitSeason/HarvestAmount/LeafHue.
  PlantFactory tints the sprite from the leaf-hue gene (combined with the
  morph variant). Plants carry a Fruiting component; PlantFruitingSystem
  ripens fruit on mature plants during their gene-chosen season and drops
  it off-season.
- plants.json: trees give wood + acorns (autumn), bushes berries (summer),
  grass gives grass — amounts/season/hue from genes.
- 'plant <species> [seed]' console command samples a species genome and
  prints its gene-driven traits and products.

Build clean; def JSON validated; boot smoke loads the new content.

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

Mods/Core/Languages/ru/ui.json

@@ -78,6 +78,11 @@
   "plant.stage.sapling": "саженец",
   "plant.stage.mature": "взрослое",
 
+  "product.wood": "древесина",
+  "product.grass": "трава",
+  "product.berry": "ягоды",
+  "product.acorn": "жёлудь",
+
   "pawn.being": "житель",
   "pawn.bear": "медведь",
   "pawn.deer": "олень",