Add shared metadata maps and stage-name helpers

internal/prompts/registry_test.go

@@ -107,3 +107,16 @@ func TestRenderedPromptsContainHardening(t *testing.T) {
 		}
 	}
 }
+
+func TestDiagnosticsMapIncludesStablePromptMetadataShapeForAllPrompts(t *testing.T) {
+	for _, m := range RegisteredMetadata() {
+		metadataMap := m.DiagnosticsMap()
+		if metadataMap["prompt_id"] != m.PromptID ||
+			metadataMap["prompt_version"] != m.PromptVersion ||
+			metadataMap["prompt_source"] != m.PromptSource ||
+			metadataMap["embedded_path"] != m.EmbeddedPath ||
+			metadataMap["sha256"] != m.SHA256 {
+			t.Fatalf("unexpected diagnostics metadata map for %q: %+v", m.PromptID, metadataMap)
+		}
+	}
+}