Add actor content scenario validation

docs/migration.md

@@ -136,6 +136,20 @@ The repository now also includes a scenario validator for common world packs:
 It verifies that selected `Outdoor*` maps reference valid `textureset` and
 environment assets across pack boundaries.
 
+It also now includes an actor/content validator:
+
+- `scripts/validate_actor_scenarios.py`
+
+On the current real client runtime, the full actor validator reports five data
+issues that look like pre-existing content inconsistencies rather than `.m2p`
+loader regressions:
+
+- `Monster/misterious_diseased_host` missing `25.gr2`
+- `Monster/skeleton_king` missing `24.gr2`
+- `Monster/thief2` missing `03_1.gr2`
+- `NPC/christmas_tree` missing `wait.gr2`
+- `NPC/guild_war_flag` missing `wait.gr2`
+
 Recommended next pack groups:
 
 1. remaining startup-adjacent patch packs