Preserve prompt origins while interpreting metadata

internal/configuration/interpretation_test.go

@@ -2,6 +2,7 @@ package configuration
 
 import (
 	"context"
+	"strings"
 	"testing"
 
 	"go.maximumdirect.net/configkit"
@@ -44,3 +45,28 @@ func TestTargetInterpretationPreservesComposedNestedValues(t *testing.T) {
 		t.Fatalf("nested field origin changed: %+v", field)
 	}
 }
+
+func TestPromptInterpretationPreservesComposedOutputAndRejectsDuplicateNames(t *testing.T) {
+	definition := map[string]any{
+		"id": "example", "inputs": []any{map[string]any{"name": " document "}},
+		"messages": []any{map[string]any{"role": "user", "content": "hello"}},
+		"output":   map[string]any{"format": "json", "validation_mode": "json_schema", "schema_path": " schema.json "},
+	}
+	state, err := load(mapping("prompt metadata", map[string]any{"prompts": []any{definition}}), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	selected, inspection, err := state.prompt("example")
+	if err != nil || selected.Validation.SchemaPath != "schema.json" || inspection.OutputContract.SchemaPath != "schema.json" || selected.Inputs[0].Name != "document" {
+		t.Fatalf("interpreted prompt = %+v, %+v, %v", selected, inspection, err)
+	}
+	composed := state.result.Config.Prompts[0]
+	if *composed.Output.SchemaPath != " schema.json " || composed.Inputs[0].Name != " document " {
+		t.Fatalf("composed prompt changed: %+v", composed)
+	}
+	definition["inputs"] = []any{map[string]any{"name": " document "}, map[string]any{"name": "document"}}
+	_, err = load(mapping("duplicate inputs", map[string]any{"prompts": []any{definition}}), nil)
+	if err == nil || !strings.Contains(err.Error(), "/prompts/0/inputs/1") || !strings.Contains(err.Error(), "duplicated") {
+		t.Fatalf("duplicate normalized names were not rejected: %v", err)
+	}
+}