Document NPC semantic normalization

docs/internal/llm.md

@@ -154,6 +154,22 @@ identity, campaign-reference, and instruction messages are ephemeral cache
 boundaries; the transcript is last and has no cache control. Compatible shared
 messages remain canonical shared assets rather than copied package text.
 
+### D&D NPC Normalization Prompt Ordering And Cache Boundaries
+
+NPC normalization has a distinct prompt and response-schema identity from NPC
+extraction. Its stable message tiers are the common D&D system and identity
+assets, followed by package-owned task and normalization instructions. Cache
+boundaries follow the shared identity tier and the package instructions. The
+variable tail contains the private candidate-name-and-range input and a
+windowed transcript input whose cited units provide local context; neither has
+a cache boundary because it changes with the document.
+
+This prompt intentionally omits extraction-evidence and campaign-reference
+assets: it reconciles existing records rather than extracting events or adding
+evidence. Its package-owned manifest and schema identity are fingerprinted
+separately, so a normalization prompt or schema change cannot reuse a prior
+normalization checkpoint.
+
 Shared wording belongs in the canonical assets under
 `internal/modules/dnd/shared`; extraction packages reference those assets in
 their manifests instead of copying similar text into package-local files.