Make configuration truthful and clean remote session files

internal/config/scriptorium_test.go

@@ -95,7 +95,7 @@ func TestScriptoriumLoadAndValidate(t *testing.T) {
 			wantValidateErr: "pipeline.scriptorium.timeout must be a valid duration",
 		},
 		{
-			name: "legacy previous session artifact source fails validation",
+			name: "legacy previous session source fails validation",
 			scriptoriumYAML: `scriptorium:
   binary: scriptorium
   artifacts:
@@ -109,8 +109,6 @@ func TestScriptoriumLoadAndValidate(t *testing.T) {
           required: true
         previous_recap:
           source: ` + legacyPreviousSource + `
-          artifact: session_recap
-          path: ""
           required: false
       vars:
         session_id: true
@@ -118,6 +116,21 @@ func TestScriptoriumLoadAndValidate(t *testing.T) {
 `,
 			wantValidateErr: `pipeline.scriptorium.artifacts.session_recap.inputs.previous_recap.source "` + legacyPreviousSource + `" is unsupported`,
 		},
+		{
+			name: "obsolete input passthrough fields fail strict decoding",
+			scriptoriumYAML: `scriptorium:
+  artifacts:
+    session_recap:
+      enabled: true
+      prompt_id: dnd.session_recap
+      output_path: artifacts/session_recap.md
+      inputs:
+        transcript:
+          source: narratio.transcript.polished
+          artifact: session_recap
+`,
+			wantLoadErr: "field artifact not found",
+		},
 		{
 			name: "canonical previous-session source is accepted",
 			scriptoriumYAML: `scriptorium: