fix(logger): expose AddSource option; FromEnv enables caller in non-dev (spec §8.2)

internal/infra/logger/logger_test.go

@@ -57,3 +57,33 @@ func TestFromEnv_NonDevelopmentUsesJSON(t *testing.T) {
 	require.NoError(t, json.Unmarshal(buf.Bytes(), &got))
 	require.Equal(t, "prod", got["msg"])
 }
+
+func TestNew_AddSourceTrue_IncludesSourceField(t *testing.T) {
+	var buf bytes.Buffer
+	log := New(Options{Format: FormatJSON, Level: LevelInfo, Writer: &buf, AddSource: true})
+	log.Info("with source")
+
+	var got map[string]any
+	require.NoError(t, json.Unmarshal(buf.Bytes(), &got))
+	require.Contains(t, got, "source", "AddSource:true 时应有 source 字段")
+}
+
+func TestNew_AddSourceFalse_OmitsSourceField(t *testing.T) {
+	var buf bytes.Buffer
+	log := New(Options{Format: FormatJSON, Level: LevelInfo, Writer: &buf, AddSource: false})
+	log.Info("without source")
+
+	var got map[string]any
+	require.NoError(t, json.Unmarshal(buf.Bytes(), &got))
+	require.NotContains(t, got, "source")
+}
+
+func TestFromEnv_NonDevelopmentEnablesSource(t *testing.T) {
+	var buf bytes.Buffer
+	log := FromEnv("production", &buf)
+	log.Info("prod log")
+
+	var got map[string]any
+	require.NoError(t, json.Unmarshal(buf.Bytes(), &got))
+	require.Contains(t, got, "source", "production 应自动开 AddSource (spec §8.2)")
+}