Panel: warn before changing the game/panel port (needs a full program restart, Docker port mapping, how to undo) so nobody locks themselves out

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Panel/app.js

@@ -356,6 +356,9 @@ function renderSettings(page) {
         if (typeof v === "number" && isNaN(v)) continue;
         body[k] = v;
       }
+      // Port geändert? Vorher warnen - sonst sperrt man sich aus (vor allem in Docker, wo der Port nicht freigegeben ist)
+      const warning = portChangeWarning(c, body);
+      if (warning && !(await modal({ title: warning.title, text: warning.text, confirm: warning.confirm }))) return;
       if (await act(api("POST", "config", body))) load();
     };
 
@@ -378,7 +381,8 @@ function renderSettings(page) {
         h("div", { class: "section-head" }, h("h2", {}, "Network & panel"), h("span", { class: "muted" }, "needs a restart")),
         h("div", { class: "section-body form-grid wide" },
           number("port", "Game port", c.port, { min: 1, max: 65535, restart: true }),
-          number("panelPort", "Panel port", c.panelPort, { min: 0, max: 65535, restart: true, hint: "0 = same port as the game (recommended)" }),
+          number("panelPort", "Panel port", c.panelPort, { min: 0, max: 65535, restart: true,
+            hint: c.inDocker ? "0 = same port as the game (recommended). Docker: another port must also be published in docker-compose.yml" : "0 = same port as the game (recommended)" }),
           text("panelBindAddress", "Panel bind address", c.panelBindAddress, { max: 60, restart: true, hint: "only with an own panel port - 127.0.0.1 = only via a local reverse proxy" }),
           text("panelBasePath", "Panel sub path", c.panelBasePath, { max: 60, restart: true, placeholder: "/", hint: "e.g. /panel when the proxy serves it there" }),
           toggle("panelTrustProxy", "Behind a reverse proxy", c.panelTrustProxy, "Trust X-Forwarded-For / -Proto / -Prefix", true),
@@ -396,6 +400,38 @@ function renderSettings(page) {
   }
 }
 
+/**
+ * Warnung, wenn Spiel- oder Panel-Port geändert werden: Ports übernimmt erst ein Neustart des ganzen Programms
+ * (der Restart-Knopf startet nur den Gameserver neu), danach ist das Panel nur noch am neuen Port - in Docker nur,
+ * wenn der Port in docker-compose.yml freigegeben ist. Text direkt in beiden Sprachen (enthält Zahlen).
+ */
+function portChangeWarning(c, body) {
+  const panelAt = (port, panelPort) => (panelPort > 0 ? panelPort : port);
+  const port = body.port ?? c.port, panelPort = body.panelPort ?? c.panelPort;
+  const oldPanel = panelAt(c.port, c.panelPort), newPanel = panelAt(port, panelPort);
+  if (port === c.port && newPanel === oldPanel) return null;
+  const de = window.MSCO_LANG === "de";
+  const lines = [];
+  if (newPanel !== oldPanel)
+    lines.push(de
+      ? `Das Panel ist danach nur noch unter Port ${newPanel} erreichbar (http://<server>:${newPanel}/), nicht mehr unter ${oldPanel}.`
+      : `Afterwards the panel is only reachable on port ${newPanel} (http://<server>:${newPanel}/), no longer on ${oldPanel}.`);
+  if (port !== c.port)
+    lines.push(de ? `Spieler verbinden sich dann über Port ${port}.` : `Players then connect on port ${port}.`);
+  lines.push(de
+    ? "Das gilt erst nach einem Neustart des ganzen Programms (docker compose restart) - der Neustart-Knopf startet nur den Gameserver neu."
+    : "This only applies after the whole program restarts (docker compose restart) - the Restart button only restarts the game server.");
+  const ports = [...new Set([port, newPanel])].map((p) => `"${p}:${p}/tcp"`).join(", ");
+  lines.push(c.inDocker
+    ? (de ? `Docker: trag vorher unter ports in docker-compose.yml ${ports} ein, sonst sperrst du dich aus.`
+          : `Docker: first add ${ports} under ports in docker-compose.yml, otherwise you lock yourself out.`)
+    : (de ? "Gib den Port in der Firewall frei." : "Open the port in your firewall."));
+  lines.push(de
+    ? 'Rückgängig: in data/server.json "PanelPort": 0 setzen und neu starten.'
+    : 'To undo: set "PanelPort": 0 in data/server.json and restart.');
+  return { title: de ? "Port ändern?" : "Change the port?", text: lines.join(" "), confirm: de ? "Trotzdem speichern" : "Save anyway" };
+}
+
 // ------------------------------------------------------------------ Spieler
 
 function renderPlayers(page) {