Validate pair seed simulation behavior

docs/prompt-architecture-improvement-plan.md

@@ -26,6 +26,8 @@ The map audit currently sees:
 - Route simulation family coverage, so representative generated rows exercise
   every registered action and position family except documented special cases
   covered by dedicated smoke fixtures.
+- Pair seed simulation, so Insta/OF soft/hard metadata and formatter outputs
+  prove locked determinism and pose-only reroll behavior.
 
 ## Architectural Finding
 
@@ -643,6 +645,8 @@ Near-term:
   scene/camera/clothing fields.
 - Keep same-room pair continuity synchronized in both assembled prompt text and
   `hardcore_row.scene_text`; `tools/prompt_smoke.py` covers this drift case.
+- Keep pair seed behavior synchronized across soft/hard rows; the route
+  simulator now checks locked pair determinism and pose-only hard-action rerolls.
 
 Medium-term: