Implement civilization flow mechanics and profiling for resource allocation

- Added `civilization_flow.gd` to manage continuous expected flows and resource allocation within civilizations.
- Introduced `allocate_profiled` and `whole_quotas` functions in `quantity_math.gd` for precise stock allocation based on float shares.
- Enhanced `credit` logic in `object_ledger.gd` to handle production remainders more effectively.
- Updated `append_batch` in `object_batches.gd` to prevent batch creation for invalid IDs.
- Introduced `ratio_approx` function in `exact.gd` for better handling of float profiles.
- Added a benchmark script `benchmark_civilization_flows.gd` to evaluate the performance of civilization flow mechanics.
- Refactored various functions to improve clarity and efficiency in handling resource flows and allocations.

tests/test_life.gd

@@ -46,7 +46,7 @@ func run() -> void:
     var before: Dictionary = world.state.duplicate(true)
     world.evolution.initialize_life_batches()
     check(E.eq(world.state, before), "Initialization is idempotent")
-    world.evolution.evolve_batches(world.state, E.add(5000000, E.divide(5000000, 40)))
+    world.evolution.evolve_batches(world.state, E.add(5000000, E.divide(5000000, root.get_node("Global").batch_count)))
     check(E.eq(world.state.amount.EON1, 10), "HP abiogenesis follows source probability")
     check(E.eq(world.state.amount.RP, 100), "HP degradation produces RP")
     check(E.eq(world.state.amount.HP, 39890), "Unchanged planets retry, not disappear")
@@ -69,7 +69,7 @@ func run() -> void:
     # Test host preservation with a fixed rate, independent of game balance.
     world.catalog.entities.EON5.life_rule.progress = "0.00025"
     world.evolution.initialize_life_batches()
-    world.evolution.evolve_batches(world.state, E.add(500000, E.divide(500000, 40)))
+    world.evolution.evolve_batches(world.state, E.add(500000, E.divide(500000, root.get_node("Global").batch_count)))
     check(E.eq(world.state.binds.RD["C0.0"], 10), "Intelligence emerges at the same host star")
     check(E.eq(world.state.amount["C0.0"], 0), "Life transition keeps planet bound")
     check(world.state.batches.has("C0.0"), "New C0.0 starts civilization evolution")