Add multi-seed route simulation sweep

docs/prompt-architecture-improvement-plan.md

@@ -36,6 +36,9 @@ The map audit currently sees:
 - Insta/OF side-target training captions no longer prepend shared cast
   descriptors when the selected side row already emits its own cast prose, and
   route simulation flags repeated cast descriptors.
+- Route simulation now has an opt-in multi-seed sweep, and the smoke suite runs
+  a three-seed sweep so representative route/noise checks are not proven by one
+  lucky seed only.
 
 ## Architectural Finding
 

docs/prompt-pool-routing-map.md

@@ -1021,9 +1021,13 @@ issues for:
   scene, soft outfit, and composition axes stable;
 - pose-axis rerolls changing cast/scene metadata or failing to move pose/action
   metadata.
+- multi-seed route sweeps that repeat the same route/noise/seed checks across
+  spaced seeds to catch random-pool drift hidden by a single clean seed.
 
 Use `--json --include-prompts` when you need the exact raw and formatted text
-for debugging a route.
+for debugging a route. Use `--sweep-count 5 --seed-step 101` when changing pool
+selection, route terms, or formatter noise rules and you need more than one
+seed of evidence.
 
 ## Editing Cheatsheet