fix(homepage): restore scheme on minecraft widget url

homepage-dashboard parses the widget url with JS's URL() and reads
.hostname/.port off the result. Without a "scheme://" prefix,
"rechberg.online:25565" parses "rechberg.online" as the scheme and
leaves hostname empty, which the minecraftstatuspinger lookup()
rejects with "No hostname was provided!" (confirmed via
journalctl -u homepage-dashboard). The scheme itself is discarded by
the widget code, so any scheme works; tcp:// documents intent since
this widget always does a plain TCP server-list ping.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HCHg6BFAjZGUZer7RW5faD

modules/environments/homepage/manual-services.nix

@@ -62,7 +62,7 @@
           icon = "minecraft.png";
           widget = {
             type = "minecraft";
-            url = "rechberg.online:25565";
+            url = "tcp://rechberg.online:25565";
           };
         };
       }