Finalize previous-session artifact documentation and restore-analyze continuity coverage

docs/config.md

@@ -73,7 +73,6 @@ Why this is sufficient:
 
 ```yaml
 session_id: "{{ session_id }}"
-previous_session_id: "{{ previous_session_id }}"
 campaign: sample-campaign
 inputs:
   audio_dir: ./audio
@@ -88,6 +87,23 @@ Usage:
 narratio run --config /path/to/pipeline.yml --session ./session.yml --session-id 2026-05-03
 ```
 
+Previous-session-enabled variant:
+
+```yaml
+session_id: "{{ session_id }}"
+previous_session_id: "{{ previous_session_id }}"
+campaign: sample-campaign
+inputs:
+  audio_dir: ./audio
+  speakers_file: ./examples/speakers.yml
+  autocorrect_file: ./examples/autocorrect.yml
+  glossary_file: ./examples/glossary.yml
+```
+
+```bash
+narratio run --config /path/to/pipeline.yml --session ./session.yml --session-id 2026-05-03 --previous-session-id 2026-04-26
+```
+
 ## 6. Production-oriented config
 
 ```yaml
@@ -132,6 +148,9 @@ scriptorium:
         transcript:
           source: narratio.transcript.trimmed
           required: true
+        previous_recap:
+          source: narratio.previous_session.artifact.session_recap
+          required: false
 ```
 
 Operational notes:
@@ -248,7 +267,6 @@ Scriptorium artifact-key and dependency rules:
 
 Allowed `pipeline.scriptorium.artifacts.<name>.inputs.<key>.source` values:
 
-- `previous_session_artifact`
 - `narratio.previous_session.artifact.<configured_artifact_key>`
 - `narratio.transcript.merged`
 - `narratio.transcript.polished`
@@ -256,6 +274,7 @@ Allowed `pipeline.scriptorium.artifacts.<name>.inputs.<key>.source` values:
 - `narratio.transcript.trimmed`
 - `narratio.bounds.session`
 - `narratio.artifact.<configured_artifact_key>`
+- `previous_session_artifact` (legacy path-based source; uses `inputs.<key>.path`)
 
 `pipeline.archive.promote_artifacts[].source` values:
 
@@ -278,7 +297,7 @@ Archive promotion destination rules:
 Restore-related implications:
 
 - restore remote identity requires archive S3 identity to resolve (`pipeline.storage.s3.bucket` and session prefix derivation inputs).
-- restore scope considers only committed current state and durable paths (`manifest.json`, `transcripts/**`, `artifacts/**`, optional `audio/**`).
+- restore scope considers committed current state and durable paths (`manifest.json`, `transcripts/**`, `artifacts/**`, `previous/**`, optional `audio/**`).
 
 ## 8. Full session reference
 
@@ -307,6 +326,7 @@ Audio-source rule:
 Previous-session rule:
 
 - if `session.previous_session_id` is set, it must not equal `session.session_id`.
+- canonical previous-session sources (`narratio.previous_session.artifact.<name>`) are hydrated during `prepare` from archive current state when required by enabled configured artifacts.
 
 ## 9. Secrets