Add comprehensive tests and optimizations for simulation and UI performance

- Introduced a new benchmark save script to create a stress test scenario with extreme values for simulation performance.
- Added a full UI benchmark script to measure frame rates and performance metrics during UI interactions.
- Implemented tests for coarse generations to ensure population transitions are handled correctly.
- Created tests for extra parameters to validate the loading and application of configuration settings.
- Developed simulation optimization tests to verify the efficiency of population drift and rounding mechanisms.
- Added split optimization tests to ensure accurate allocation and rounding behavior in population management.
- Included startup parameter tests to confirm the correct initialization of global parameters before scene readiness.
- Enhanced the audit rounding ledger to compare selective and full rounding results for consistency.

tests/test_startup_params.gd

@@ -0,0 +1,14 @@
+extends SceneTree
+const E = preload("res://world/owniverse/math/exact.gd")
+func _initialize():
+    # SceneTree initialization runs before Global._ready, like main scene construction.
+    var global = root.get_node("Global")
+    assert(not global.is_node_ready(), "Test must cover pre-ready initialization")
+    assert(global.ExtraParams.has("E"), "Energy table exists before Global._ready")
+    var scene = load("res://world/world.tscn").instantiate()
+    var stage = scene.get_node("Stage")
+    assert(E.eq(stage.owniverse.state.energy, global.ExtraParams.E), "Stage starts with configured energy")
+    stage.owniverse.free()
+    scene.free()
+    print("Startup params: 3 checks, 0 failures")
+    quit()