feat: establish simulation scaling baseline

docs/BUILD_IN_PUBLIC_PLAN.md

@@ -750,14 +750,19 @@ Completed:
     derives one concise ordinary harvest route from current player-usable finite
     resources and the real pantry or woodpile. It clears when help emerges or
     the need closes, and adds no quest, waypoint, tracker, or saved UI state.
+32. Deterministic scaling baseline: one schema-valid full-fidelity fixture now
+    drives a repeatable CLI ledger and fast headless regression across rising
+    NPC and event counts. The first reviewed capture sets a local 600-NPC target,
+    records identical checksums across samples, and exposes repeated scarce-food
+    population scans plus objective-event growth as the next measured work.
 
 Next:
 
-1. Begin Milestone 8 with a deterministic headless scaling baseline over
-   increasing NPC and event counts. Measure current tick throughput,
-   serialized-state growth, and retained history before choosing a target
-   population or adding spatial partitions and simulation LOD, as sequenced in
-   `LEARNING_ROADMAP.md`.
+1. Reuse one stable per-tick population view in the existing
+   trusted-starving-subject query, preserve exact action/checksum behavior, and
+   rerun simulation scaling baseline 01. Let the resulting profile determine
+   whether the following slice needs another bounded query optimization, a
+   spatial index, or the first active/abstract LOD contract.
 
 Do not start with GIS data, a full city, a large asset pack, or more NPC
 mechanics. The next proof is a beautiful stage for the systems that already