Document prepared Notarius references

docs/internal/stage-prepare.md

@@ -8,6 +8,7 @@ Materialize canonical current-session inputs before processing stages.
 
 - resolved campaign, session, and pipeline configuration
 - stable input files (`speakers`, `autocorrect`, `glossary`, `players`, `party`)
+- optional spell-catalog overlay
 - one resolved local or S3 audio source
 - enabled configured artifact input requirements for previous-session sources
 
@@ -21,6 +22,7 @@ Materialize canonical current-session inputs before processing stages.
 - `inputs/glossary.yml`
 - `inputs/players.yml`
 - `inputs/party.yml`
+- optional `inputs/spell_catalog.json`
 - `audio/*.flac`
 - optional `previous/manifest.json`
 - optional `previous/artifacts/**`
@@ -34,6 +36,9 @@ Materialize canonical current-session inputs before processing stages.
 - gives distinct local source paths with the same basename deterministic unique
   prepared filenames so neither source is overwritten.
 - materializes S3 audio through spool/cache-aware logic.
+- materializes a configured spell catalog with checksum and provenance, or
+  safely removes an obsolete canonical spell catalog and its manifest record
+  when the effective input is omitted.
 - scans enabled configured artifact inputs for `narratio.previous_session.artifact.*` requirements.
 - clears managed `previous/` state on every invocation, then, when requirements exist:
   - resolves the pointer-selected previous source through the shared resolver;