one-time hints; builder touchups

src/components/chart/DiagonalBuilder.vue

@@ -89,6 +89,7 @@
         </tr>
       </tbody>
     </table>
+    <one-time-hint name="click-chart" activator="#tv-widget" location="center" :when="builder.lineA===null && !co.drew" text="Click the chart!"/>
   </rung-builder>
 </template>
 
@@ -102,6 +103,7 @@ import {allocationText, DLine} from "@/charts/shape.js";
 import {vectorEquals, vectorInterpolate} from "@/vector.js";
 import AbsoluteTimeEntry from "@/components/AbsoluteTimeEntry.vue";
 import {useStore} from "@/store/store.js";
+import OneTimeHint from "@/components/OneTimeHint.vue";
 
 const s = useStore()
 const co = useChartOrderStore()