fix(auth, executor): normalize Qwen base URL, adjust RefreshLead duration, and add tests

sdk/auth/qwen_refresh_lead_test.go

@@ -0,0 +1,19 @@
+package auth
+
+import (
+	"testing"
+	"time"
+)
+
+func TestQwenAuthenticator_RefreshLeadIsSane(t *testing.T) {
+	lead := NewQwenAuthenticator().RefreshLead()
+	if lead == nil {
+		t.Fatal("RefreshLead() = nil, want non-nil")
+	}
+	if *lead <= 0 {
+		t.Fatalf("RefreshLead() = %s, want > 0", *lead)
+	}
+	if *lead > 30*time.Minute {
+		t.Fatalf("RefreshLead() = %s, want <= %s", *lead, 30*time.Minute)
+	}
+}