add ai feature

internal/ai/flow/prompt_test.go

@@ -0,0 +1,34 @@
+package flow_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/rogeecn/renamer/internal/ai/flow"
+)
+
+func TestRenderPromptIncludesFilesAndPrompt(t *testing.T) {
+	input := flow.RenameFlowInput{
+		FileNames:  []string{"IMG_0001.jpg", "albums/Day 1.png"},
+		UserPrompt: "按地点重新命名",
+	}
+
+	rendered, err := flow.RenderPrompt(input)
+	if err != nil {
+		t.Fatalf("RenderPrompt error: %v", err)
+	}
+
+	for _, expected := range []string{"IMG_0001.jpg", "albums/Day 1.png"} {
+		if !strings.Contains(rendered, expected) {
+			t.Fatalf("prompt missing filename %q: %s", expected, rendered)
+		}
+	}
+
+	if !strings.Contains(rendered, "按地点重新命名") {
+		t.Fatalf("prompt missing user guidance: %s", rendered)
+	}
+
+	if !strings.Contains(rendered, "suggestions") {
+		t.Fatalf("prompt missing JSON structure guidance: %s", rendered)
+	}
+}