Add comprehensive civilization evolution tests and enhance civilization state management

- Introduced a new test script for civilization evolution (`test_civilization_evolution.gd`) to validate the evolution mechanics, including population dynamics, ethical transitions, and war impacts.
- Updated `README.md` to include instructions for running the new civilization evolution tests.
- Modified `test_civilization_state.gd` to accommodate changes in civilization rules and ensure proper validation of ethical stages.
- Enhanced `test_descriptions.gd` to check for accurate population counters and state validation.
- Adjusted `test_life.gd` to reflect updates in life version management.
- Improved `civilization_state.gd` to include habitat budget calculations and transition management.
- Added `civilization_evolution.gd` to handle the logic for civilization evolution, including population drift, warfare, and colonization mechanics.
- Updated `owniverse.gd` and `owniverse_entity.gd` to integrate new evolution logic and ensure proper initialization of entities.

tests/test_descriptions.gd

@@ -62,6 +62,14 @@ func run() -> void:
     check(values.amount.contains("#ff6060") and values.amount.contains("−2.0"), "Real-time decrease red")
     values = description.variables(world, global, "HP")
     check(values.amount == "7", "Planet description includes bound planets")
+    world.state.amount.EON1 = 2.0
+    world.state.binds.G.EON2 = 3.0
+    var saved_state: Dictionary = world.state.duplicate(true)
+    var counters: Dictionary = world.get_item_amounts()
+    check(counters.HP == 7.0 and counters.LP == 5.0 and counters.Planet == 12.0, "Planet counters include bound objects and aggregate eons")
+    check(counters.RD == 2.0, "Star counters retain available quantity")
+    check(world.state == saved_state, "Reading counters does not mutate simulation")
+    check(world.get_item_amounts(true).HP == 0.0, "Produced counters remain independent of current population")
     values = description.variables(world, global, "RD", 2.0)
     check(values.amount.contains("#40cc40") and values.amount.contains("+2.0"), "Increase green")
     var stage_script = load("res://stage/stage.gd")