Generalize welcome message

This will be helpful in preparation for the next step: Timeout on idle.

src/App.tsx

@@ -56,7 +56,7 @@ function App() {
   const [album, setAlbum] = useState<AlbumType | null>(null);
   const [buffer, setBuffer] = useState<string[]>([]);
   const [nowPlaying, play] = useState<number>(0);
-  const [searching, setSearching] = useState(false);
+  const [displayText, setDisplayText] = useState("Scan an album to begin.");
   const [paused, setPaused] = useState(true);
   const [currentTime, setCurrentTime] = useState(0);
   const [duration, setDuration] = useState(0);
@@ -129,7 +129,7 @@ function App() {
       console.log("empty barcode; ignoring");
       return;
     }
-    setSearching(true);
+    setDisplayText("Searching…");
     console.log("Scanned barcode:", barcode);
     var mbRelease: IRelease | IReleaseMatch;
     if (barcode.startsWith("mbid:")) {
@@ -145,8 +145,8 @@ function App() {
         inc: ['artist-credits', 'release-groups', 'genres'], // TODO
       });
       if (searchResponse.count === 0) {
-        console.log("No album found for barcode:", barcode); // TODO: some kind of toast?
-        setSearching(false);
+        setDisplayText("No album found for barcode: " + barcode);
+        setTimeout(() => setDisplayText("Scan an album to begin."), 3000);
         return;
       }
       mbRelease = searchResponse.releases[0];
@@ -179,7 +179,6 @@ function App() {
       // # …and play!
       play(0);
       setPaused(false);
-      setSearching(false);
     } else { // Not found in Navidrome; populate with MusicBrainz data instead
       const fullMbRelease = await mbApi.lookup('release', mbRelease.id, ['recordings', 'artist-credits', 'release-groups']);
       const tracks: Track[] = fullMbRelease.media[0].tracks.map((t: ITrack) => ({ // TODO: handle multi-disc albums
@@ -196,7 +195,6 @@ function App() {
         coverArtLink: await getCoverArtSrcURL(fullMbRelease.id, fullMbRelease['release-group']?.id || '') || '',
       })
       console.log(album);
-      setSearching(false);
     }
   }
 
@@ -231,10 +229,8 @@ function App() {
         {player}
       </div>
     )
-  } else if (searching) {
-    return (<div className="welcome">Searching…</div>);
   } else {
-    return (<div className="welcome">Scan an album to begin.</div>);
+    return (<div className="welcome">{displayText}</div>);
   }
 }