Weight system: body mass, carry capacity, Kleiber metabolism

Mass is derived by a cubic law: mass = BaseMassKg * (size / reference)^3, so a
juvenile/seedling weighs far less than an adult/mature and the size gene moves
mass too. New Mass helper + BaseMassKg on AnimalDef/PlantDef (deer 70, wolf 45,
boar 80, chicken 2.5; trees ~450, grass 0.4, etc.) and MassKg per unit on
ProductDef (foundation for hauling/inventory).

Wired into the sim (as chosen):
- Corpse meat is now proportional to body mass (Mass.MeatFraction), not raw
  bodySize; Corpse gained a BodySize field so sprite scale stays independent of
  meat (save/load updated).
- Kleiber metabolism: need decay x= (mass/refMass)^0.75, normalized per species,
  so juveniles are cheaper to feed and heavier individuals eat a bit more,
  without cross-species balance blowups (adults of typical size are unchanged).
- Carry capacity = mass x fraction x carry capability (Moving for quadrupeds;
  Manipulation for future humans), shown in inspector/console. A dormant Carrier
  component + Mass.LoadSpeedFactor hook slow an overloaded animal — the
  foundation for item hauling.

Inspector shows body/plant weight (+carry); `animal`/`plant` console print mass.
Build + --check-content clean (42 genes, 41 traits). Not GUI-verified.

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

Mods/Core/Defs/Plants/_Bases.json

@@ -4,6 +4,7 @@
   // через "parent" и лежат рядом в файлах по семействам (Trees, Bushes, Cacti, …).
   "defs": [
     { "defName": "BaseTree", "abstract": true, "sizeCells": 2.0, "trunkRadiusCells": 0.28,
+      "baseMassKg": 450,
       "harvestProduct": "ProductWood", "fruitProduct": "ProductAcorn",
       "genome": { "optimalLight": 0.6, "lightTolerance": 0.5, "optimalTemperature": 14, "temperatureTolerance": 10,
                   "coldHardiness": 14, "heatHardiness": 12,
@@ -19,6 +20,7 @@
 
     // Деревья тёплой и холодной температурных ниш (showcase температурных генов).
     { "defName": "BaseWarmTree", "abstract": true, "sizeCells": 2.0, "trunkRadiusCells": 0.28,
+      "baseMassKg": 420,
       "harvestProduct": "ProductWood", "fruitProduct": "ProductAcorn",
       "genome": { "optimalLight": 0.65, "lightTolerance": 0.5, "optimalTemperature": 23, "temperatureTolerance": 9,
                   "coldHardiness": 8, "heatHardiness": 16,
@@ -32,6 +34,7 @@
         { "sizeCells": 2.0, "label": "plant.stage.mature" }
       ] },
     { "defName": "BaseColdTree", "abstract": true, "sizeCells": 2.0, "trunkRadiusCells": 0.26,
+      "baseMassKg": 500,
       "harvestProduct": "ProductWood", "fruitProduct": "ProductAcorn",
       "genome": { "optimalLight": 0.55, "lightTolerance": 0.5, "optimalTemperature": 8, "temperatureTolerance": 12,
                   "coldHardiness": 18, "heatHardiness": 8,
@@ -46,6 +49,7 @@
       ] },
 
     { "defName": "BaseBush", "abstract": true, "label": "plant.bush", "sizeCells": 1.4,
+      "baseMassKg": 6,
       "fruitProduct": "ProductBerry",
       "genome": { "optimalLight": 0.6, "lightTolerance": 0.5, "optimalTemperature": 17, "temperatureTolerance": 9,
                   "coldHardiness": 10, "heatHardiness": 8,
@@ -60,6 +64,7 @@
 
     // Кактусы: жаролюбивы, засухоустойчивы (низкий оптимум почвы), морозо-нестойки → гибнут в морозы.
     { "defName": "BaseCactus", "abstract": true, "label": "plant.cactus", "sizeCells": 1.2, "trunkRadiusCells": 0,
+      "baseMassKg": 35,
       "harvestProduct": "ProductFiber",
       "genome": { "optimalLight": 0.95, "lightTolerance": 0.35, "optimalTemperature": 26, "temperatureTolerance": 8,
                   "coldHardiness": 20, "heatHardiness": 18,
@@ -76,6 +81,7 @@
     // Грибы: подлесок леса. Низкий оптимум света (0.15) → растут в тени крон, где другим темно
     // (showcase световой пригодности). Богатая почва, короткая жизнь, быстрое спороношение.
     { "defName": "BaseMushroom", "abstract": true, "label": "plant.mushroom", "sizeCells": 0.9, "trunkRadiusCells": 0,
+      "baseMassKg": 0.3,
       "harvestProduct": "ProductMushroom",
       "genome": { "optimalLight": 0.15, "lightTolerance": 0.22, "optimalTemperature": 14, "temperatureTolerance": 11,
                   "coldHardiness": 12, "heatHardiness": 8,
@@ -91,6 +97,7 @@
 
     // Луг: цветы (декоративные, быстрое расселение) и ягодный почвопокров (еда).
     { "defName": "BaseFlower", "abstract": true, "label": "plant.flower", "sizeCells": 1.0, "trunkRadiusCells": 0,
+      "baseMassKg": 0.15,
       "genome": { "optimalLight": 0.9, "lightTolerance": 0.35, "optimalTemperature": 20, "temperatureTolerance": 9,
                   "coldHardiness": 8, "heatHardiness": 8,
                   "optimalFertility": 1.0, "fertilityTolerance": 1.1, "vigor": 1.4,
@@ -103,6 +110,7 @@
       ] },
 
     { "defName": "BaseBerryBush", "abstract": true, "label": "plant.berrybush", "sizeCells": 1.2, "trunkRadiusCells": 0,
+      "baseMassKg": 5,
       "fruitProduct": "ProductBerry",
       "genome": { "optimalLight": 0.8, "lightTolerance": 0.4, "optimalTemperature": 18, "temperatureTolerance": 9,
                   "coldHardiness": 10, "heatHardiness": 7,