Rewrite docs for the publish stage contract and current behavior

docs/internal/artifacts.md

@@ -15,8 +15,8 @@ Inputs:
 Outputs:
 - resolved artifact path + provenance (`ResolvedSessionArtifact`);
 - runtime catalog entries for built-ins and configured artifacts;
-- requirement sets for canonical previous-session inputs.
-- canonical S3 session, run, current, session config, session locks, audio, and promoted artifact keys.
+- requirement sets for canonical previous-session inputs;
+- canonical S3 session, run, current, session config, session locks, audio, and published output keys.
 
 ## Boundaries
 Owns:
@@ -28,7 +28,7 @@ Owns:
 Does not own:
 - prepare-stage remote hydration;
 - stage success/skip transitions;
-- archive upload orchestration.
+- publish upload orchestration.
 
 ## Built-in IDs
 | Artifact ID | Canonical file | Producer stage | Output kind |
@@ -71,7 +71,7 @@ Previous-session canonical provenance values include:
 - Built-ins resolve via manifest producer outputs first, then canonical fallback paths.
 - Configured `narratio.artifact.<name>` sources resolve through catalog availability.
 - Canonical previous-session sources resolve to current-session `previous/` cache candidates derived from configured artifact canonical output paths.
-- Archive-relative configured artifact paths under `artifacts/` are cached without a redundant nested `artifacts/` segment.
+- Publish-relative configured artifact paths under `artifacts/` are cached without a redundant nested `artifacts/` segment.
 - Previous-session canonical resolution prefers manifest-recorded input paths when present, then filesystem fallback under `previous/artifacts/**`.
 
 ## Previous-session requirement scanning