Capture keyed prompts and source-backed content at load time

internal/usecase/runner.go

@@ -5,7 +5,6 @@ import (
 	"crypto/sha256"
 	"encoding/binary"
 	"encoding/hex"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"hash"
@@ -809,10 +808,5 @@ func buildOutputArtifact(content string, format domain.OutputFormat) domain.Arti
 }
 
 func hashPromptDefinition(def *domain.PromptDefinition) (string, error) {
-	b, err := json.Marshal(def)
-	if err != nil {
-		return "", err
-	}
-	sum := sha256.Sum256(b)
-	return hex.EncodeToString(sum[:]), nil
+	return promptdef.HashDefinition(def)
 }