Dashboard Studio 1.6.1: show version, load fresh files after updates

- Version shown under About in the dashboard settings, with a link to
  the repository; /api/version reports it
- index.html is never cached and stamps the version on every asset URL,
  so browsers can't keep running old files after an update
- Open screens check the version after reconnecting and every 5 minutes
  and reload into the new version (editing only shows a message);
  pending saves are flushed first

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

dashboard_studio/web/app.js

@@ -4,6 +4,9 @@
   const Widgets = window.Widgets;
   const Icons = window.Icons;
   const tr = window.I18n.t, LOCALE = window.I18n.locale;
+  // Filled in by the server; "dev" when index.html is opened some other way.
+  const APP_VERSION = (document.querySelector('meta[name="ds-version"]')?.content || "dev").replace("__VERSION__", "dev");
+  const REPO_URL = "https://git.melvanveen.nl/veenm/ha-dashboard-studio";
   /** Option labels: a direct translation when there is one, else the capitalised value. */
   const optLabel = (o) => (tr(o) !== o ? tr(o) : tr(cap(String(o).replace("-", " "))));
   const $ = (s, el = document) => el.querySelector(s);
@@ -245,13 +248,15 @@
   let metrics = { colW: 0, rh: 72, gap: 14, cols: 12, compact: false };
 
   // ------------------------------------------------------------ persistence
-  let saveTimer = null;
+  let saveTimer = null, savePending = false;
   function scheduleSave() {
+    savePending = true;
     $("#save-status").textContent = tr("Saving…");
     clearTimeout(saveTimer);
     saveTimer = setTimeout(save, 700);
   }
   async function save() {
+    savePending = false;
     try {
       const r = await fetch(new URL("api/dashboards", BASE), { method: "PUT", headers: { "Content-Type": "application/json" }, body: JSON.stringify(store) });
       if (!r.ok) throw new Error(r.status);
@@ -677,6 +682,11 @@
       <div class="section"><div class="section-title">${tr("Language")}</div>
         ${fieldHTML({ k: "lang", t: "select", l: "Language on this device", o: Object.keys(window.I18n.languages), labels: Object.fromEntries(Object.entries(window.I18n.languages).map(([c, n]) => [c, c === "auto" ? tr(n) : n])) }, window.I18n.preference(), "device")}
       </div>
+      <div class="section"><div class="section-title">${tr("About")}</div>
+        <div class="about"><img src="static/favicon.png?v=${esc(APP_VERSION)}" alt="" width="40" height="40">
+          <div><div style="font-weight:600">Dashboard Studio</div><div class="muted small">${tr("Version {0}", esc(APP_VERSION))}</div></div></div>
+        <a class="btn" href="${REPO_URL}" target="_blank" rel="noopener" style="width:100%;margin-top:10px;text-decoration:none">${Icons.svg("globe")}${tr("Source code and changes")}</a>
+      </div>
       <p class="hint">${tr("Select a widget to edit it.")}</p>`;
   }
 
@@ -1369,7 +1379,27 @@
     const c = $("#conn");
     c.classList.toggle("ok", ok);
     c.textContent = ok ? tr("Connected") : tr("Offline");
+    // An update restarts the app, which drops the connection: check right after reconnecting.
+    if (ok) checkVersion();
   };
+
+  /** If the app was updated while this page was open, load the new version. */
+  let updateNoticeShown = false;
+  async function checkVersion() {
+    if (APP_VERSION === "dev") return;
+    let latest;
+    try { latest = (await api("api/version")).version; } catch { return; }
+    if (!latest || latest === APP_VERSION) return;
+    if (editMode) { // never yank the editor away; just say so once
+      if (!updateNoticeShown) toast(tr("Dashboard Studio was updated to {0}. Reload the page to use it.", latest));
+      updateNoticeShown = true;
+      return;
+    }
+    toast(tr("Dashboard Studio was updated to {0}. Reloading…", latest));
+    if (savePending) { clearTimeout(saveTimer); await save(); } // keep edits still waiting to be saved
+    setTimeout(() => location.reload(), 2500);
+  }
+  setInterval(checkVersion, 5 * 60 * 1000);
   ha.onChange = onStateChange;
 
   /** Translate the static page: elements marked data-i18n, plus every aria-label and title. */