test(antigravity): check tool config assertions

backend/internal/service/antigravity_gateway_compat_test.go

@@ -254,7 +254,8 @@ func TestBuildAntigravityCompatGeminiBody_ConfiguresMixedToolInvocations(t *test
 
 			var wrapped map[string]any
 			require.NoError(t, json.Unmarshal(body, &wrapped))
-			request := wrapped["request"].(map[string]any)
+			request, ok := wrapped["request"].(map[string]any)
+			require.True(t, ok)
 			toolConfig, exists := request["toolConfig"].(map[string]any)
 			if !tt.wantField {
 				require.False(t, exists)

backend/internal/service/antigravity_gateway_service_test.go

@@ -370,8 +370,10 @@ func TestAntigravityGatewayService_ForwardGemini_PreservesServerSideToolInvocati
 
 	var wrapped map[string]any
 	require.NoError(t, json.Unmarshal(upstream.requestBodies[0], &wrapped))
-	request := wrapped["request"].(map[string]any)
-	toolConfig := request["toolConfig"].(map[string]any)
+	request, ok := wrapped["request"].(map[string]any)
+	require.True(t, ok)
+	toolConfig, ok := request["toolConfig"].(map[string]any)
+	require.True(t, ok)
 	require.Equal(t, true, toolConfig["includeServerSideToolInvocations"])
 	require.NotContains(t, toolConfig, "include_server_side_tool_invocations")
 }