Forced drops bank honestly; half-dead sockets confess

DROP OBJECT's forced drop hardcoded onHomeOf null and skipped the
victory check — a treasure shaken loose over a home square neither
reported the banking nor triggered scoring or the captured-treasures
clause until something else prodded the engine. It now lands like any
drop: homeOwnerAt reported, checkVictory immediate.

And the stuck-game mystery from 38YP: a deploy restart left the
browser holding a half-dead socket that never fired onclose, so the
existing reconnect loop and masthead banner never engaged and a live
game wore a frozen face. The client now pings every 15s and force-
closes a socket silent for 45s, which wakes the reconnect machinery;
the server answers pong.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015RCWSTnb1KYTPyL4GmhGnF

packages/server/src/index.ts

@@ -475,6 +475,12 @@ wss.on("connection", (socket) => {
 
     try {
       switch (msg.type) {
+        case "ping":
+          // Liveness probe: the reply is the point. A restart can leave
+          // browsers holding half-dead sockets that never fire onclose;
+          // silence answered by silence is how the client finds out.
+          send(socket, { type: "pong" });
+          break;
         case "create": {
           const name = cleanName(msg.name);
           if (!name) return send(socket, { type: "error", message: "name required" });