perf: benchmark regional simulation scale

docs/benchmarks/README.md

@@ -24,8 +24,24 @@ Loaded-resource discovery has its own bounded runner:
   --script res://tools/benchmark_loaded_resource_discovery.gd
 ```
 
+The regional record/scheduler workload has a separate honest runner:
+
+```bash
+/Applications/Godot.app/Contents/MacOS/Godot \
+  --headless --path "$PWD" \
+  --script res://tools/benchmark_regional_scale.gd
+```
+
+It constructs five settlements, 20 caravans, 2,000 named people, 50,000
+aggregate residents, and 2,025 deterministic due jobs. It measures record
+construction, canonical roundtrip, scheduler construction, and job draining;
+it does not claim rendered or full-economy throughput.
+
 Reviewed captures:
 
+- [Regional scale baseline 01](REGIONAL_SCALE_BASELINE_01.md) records the
+  primitive regional state and deterministic scheduler workload at five
+  settlements, 20 caravans, 2,000 named people, and 50,000 aggregate residents.
 - [Simulation scaling baseline 01](SIMULATION_SCALING_BASELINE_01.md) records
   the first full-fidelity population/history measurements and the bounded next
   optimization.