Add merge references and retry config

docs/troubleshooting.md

@@ -118,16 +118,18 @@ Symptoms include:
 
 Fix:
 
-- Confirm the selected chunker, extractor, or normalizer declares the slot. The
+- Confirm the selected chunker, extractor, merger, or normalizer declares the slot. The
   implemented `dnd/scenes` chunker and `dnd/spells` extractor declare optional
   `roster` and `glossary` slots.
 - Use a specific selector when more than one selected target declares the same
-  slot. Examples include `chunk.context=./context.txt`,
-  `spells.extract.context=./extract-context.txt`, and
+  slot: `chunk.context=./context.txt`,
+  `spells.extract.context=./extract-context.txt`,
+  `spells.merge.context=./merge-context.txt`, or
   `spells.normalize.context=./normalize-context.txt`.
-- `lane.slot=path` is valid only when exactly one selected extractor or
-  normalizer in that lane declares the slot. If both do, use
-  `lane.extract.slot=path` or `lane.normalize.slot=path`.
+- `lane.slot=path` is valid only when exactly one selected extractor, merger,
+  or normalizer in that lane declares the slot. If more than one does, use
+  `lane.extract.slot=path`, `lane.merge.slot=path`, or
+  `lane.normalize.slot=path`.
 - Use `--without-reference selector` to remove optional config bindings; do not
   pass an empty `--reference selector=`.
 - Check whether a path came from config or CLI. Config paths are relative to