Define release-candidate balance acceptance targets

MEMORY.md

@@ -4,6 +4,14 @@ Session memory for durable decisions, state, and gotchas. Keep concise, remove o
 
 ## Decisions
 
+- **0.10.0 balance protocol:** `docs/balance-acceptance.md` defines targets and
+  denominator/cohort rules for the 36 venue/difficulty/phase cells, seeds 1–100,
+  access/emergency error rates and matched calm vs emergency-first comparisons.
+  These are acceptance criteria, not measured results; sweeps/playtests remain open.
+  Inspection found `_read_npc_truth()` is type-derived, not behavior-derived;
+  the pending emergency fairness review must cover this oracle mismatch rather
+  than treating internal truth as independent evidence.
+
 - The visual-alignment path/loader/panel/HUD work and the realism lighting pass are complete and
   recorded in `DONE.md`; remaining visual items are the realism follow-ups in `TODO.md`.
 - **Character mesh cap (2026-11-02):** the eight library variants now use **8,000 triangles /