Register D&D scene chunker

docs/config.md

@@ -167,6 +167,7 @@ one configured profile.
 | --- | --- | --- |
 | input | `seriatim` | Reads Seriatim transcript JSON. |
 | chunk | `generic` | Splits source units into ordered chunks. |
+| chunk | `dnd/scenes` | Uses an LLM to split transcript source units into D&D scenes. |
 | extract | `dnd/spells` | Extracts `dnd.spell_cast` artifacts. |
 | merge | `appendorder` | Keeps candidates in append order. |
 | normalize | `noop` | Passes merged artifacts through unchanged. |
@@ -178,6 +179,9 @@ The `generic` chunker accepts:
 - `overlap_units`: non-negative integer, default `0`, and must be less than
   `max_units`.
 
+The `dnd/scenes` chunker requires transcript source capabilities, calls the
+configured structured LLM provider, and does not accept module options.
+
 ## Diagnostics
 
 `diagnostics` fields: