Add admin presence timing settings

public/admin.css

@@ -1328,6 +1328,16 @@ label { display: grid; gap: 6px; color: var(--muted); font-size: 13px; }
   padding: 0;
   accent-color: var(--brand);
 }
+.seconds-field {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) auto;
+  gap: 7px;
+  align-items: center;
+}
+.seconds-field span {
+  color: var(--muted);
+  font-size: 12px;
+}
 pre {
   white-space: pre-wrap;
   overflow: auto;

public/admin.html

@@ -181,6 +181,20 @@
           </section>
           <section class="settings-tab-panel" data-settings-panel="admin">
             <div class="admin-preferences">
+              <fieldset class="effect-settings presence-settings">
+                <legend>Signalizace navstevniku</legend>
+                <p class="ai-help">Zelena znamena aktivni. Po necinosti se prepne na oranzovou a po dalsim limitu na sedou.</p>
+                <div class="settings-top-row">
+                  <label>Zelena do
+                    <span class="seconds-field"><input id="presenceActiveSeconds" type="number" min="10" max="3600" step="5"><span>s</span></span>
+                  </label>
+                  <label>Seda po
+                    <span class="seconds-field"><input id="presenceOfflineSeconds" type="number" min="20" max="7200" step="5"><span>s</span></span>
+                  </label>
+                </div>
+                <small id="presenceStatus" class="full-row">Oranzova je cas mezi zelenou a sedou.</small>
+                <button id="savePresenceSettings" class="full-row" type="button">Ulozit signalizaci</button>
+              </fieldset>
               <fieldset class="effect-settings sound-settings">
                 <legend>BO zvuk</legend>
                 <label class="setting-switch full-row">Zvuk notifikaci <input id="adminSoundToggleSettings" type="checkbox"></label>

public/admin.js

@@ -71,6 +71,9 @@ $("#logoutButton").addEventListener("click", async () => {
 
 $("#settingsButton").addEventListener("click", () => $("#settingsPanel").classList.toggle("hidden"));
 $("#closeSettingsButton").addEventListener("click", () => $("#settingsPanel").classList.add("hidden"));
+$("#presenceActiveSeconds").addEventListener("input", markPresenceSettingsDirty);
+$("#presenceOfflineSeconds").addEventListener("input", markPresenceSettingsDirty);
+$("#savePresenceSettings").addEventListener("click", savePresenceSettings);
 $("#adminSoundToggle").addEventListener("click", () => {
   setAdminSoundMuted(!state.soundMuted);
 });
@@ -522,6 +525,7 @@ function renderSite() {
     ? `Klic ulozeny (${s.translations.openaiApiKeyMasked || "sk-..."})`
     : "Klic neni ulozeny. Bez nej AI preklady nepobezi.";
   renderModelOptions(s.translations?.model || "gpt-5-mini");
+  renderPresenceSettings(s.adminPresence || {});
   renderTelegramSettings(s.telegram || {});
 }
 
@@ -757,6 +761,52 @@ function setOpenAiStatus(message) {
   $("#openaiApiKeyStatus").textContent = message;
 }
 
+function renderPresenceSettings(settings) {
+  const normalized = normalizePresenceSettings(settings);
+  $("#presenceActiveSeconds").value = normalized.activeSeconds;
+  $("#presenceOfflineSeconds").value = normalized.offlineSeconds;
+  setPresenceStatus(`Oranzova: ${normalized.activeSeconds}-${normalized.offlineSeconds} s necinosti.`);
+}
+
+function markPresenceSettingsDirty() {
+  const normalized = normalizePresenceSettings({
+    activeSeconds: $("#presenceActiveSeconds").value,
+    offlineSeconds: $("#presenceOfflineSeconds").value
+  });
+  setPresenceStatus(`Neulozeno. Oranzova bude ${normalized.activeSeconds}-${normalized.offlineSeconds} s.`);
+}
+
+async function savePresenceSettings() {
+  if (!state.site) return;
+  const normalized = normalizePresenceSettings({
+    activeSeconds: $("#presenceActiveSeconds").value,
+    offlineSeconds: $("#presenceOfflineSeconds").value
+  });
+  setPresenceStatus("Ukladam signalizaci...");
+  const settings = structuredClone(state.site.settings);
+  settings.adminPresence = normalized;
+  await saveSite({ settings, isOnline: state.site.isOnline });
+  renderPresenceSettings(state.site.settings.adminPresence || normalized);
+  await Promise.all([loadConversations(), loadVisitors()]);
+  setPresenceStatus(`Ulozeno. Oranzova: ${normalized.activeSeconds}-${normalized.offlineSeconds} s.`);
+}
+
+function normalizePresenceSettings(value = {}) {
+  const activeSeconds = clampNumber(value.activeSeconds, 10, 3600, 30);
+  const offlineSeconds = Math.max(clampNumber(value.offlineSeconds, 20, 7200, 120), activeSeconds + 10);
+  return { activeSeconds, offlineSeconds };
+}
+
+function clampNumber(value, min, max, fallback) {
+  const number = Number(value);
+  if (!Number.isFinite(number)) return fallback;
+  return Math.min(max, Math.max(min, Math.round(number)));
+}
+
+function setPresenceStatus(message) {
+  $("#presenceStatus").textContent = message;
+}
+
 function renderTelegramSettings(settings) {
   $("#telegramEnabled").checked = Boolean(settings.enabled);
   $("#telegramOperatorName").value = settings.operatorName || "Alex";