Show Live/Ended status on LiveTrack sessions

A session's own end timestamp is absent until the activity is
actually stopped, so its presence/absence is the status signal — no
new data needed, just reading what was already there. Shown as a
badge next to the session in the list and in its map hover popup.

public/js/livetrack.js

@@ -90,7 +90,11 @@ export class LiveTrackPanelControl {
       timeSpan.className = "livetrack-panel__time";
       timeSpan.textContent = new Date(received_at).toLocaleString();
 
-      button.append(labelSpan, timeSpan);
+      if (summary) {
+        button.append(statusBadge(summary.active), labelSpan, timeSpan);
+      } else {
+        button.append(labelSpan, timeSpan);
+      }
       button.addEventListener("click", () => this._toggleTrack(id, button));
       li.appendChild(button);
       this._list.appendChild(li);
@@ -213,8 +217,9 @@ export class LiveTrackPanelControl {
 // data — session_name in particular is user-supplied (whatever the LiveTrack
 // session was named on the watch/app) — so escape before it lands in HTML,
 // same as GpxPanelControl's popups do for GPX file contents.
-function popupHtml({ session_name, activity_type, distance_meters, duration_secs, time, speed_meters_per_sec, heart_rate_beats_per_min }) {
-  const parts = [`<strong>${escapeHtml(session_name || "LiveTrack session")}</strong>`];
+function popupHtml({ session_name, activity_type, distance_meters, duration_secs, active, time, speed_meters_per_sec, heart_rate_beats_per_min }) {
+  const status = active ? `<span class="livetrack-badge livetrack-badge--live">Live</span>` : `<span class="livetrack-badge">Ended</span>`;
+  const parts = [`<strong>${escapeHtml(session_name || "LiveTrack session")}</strong> ${status}`];
 
   const stats = [];
   if (activity_type) stats.push(escapeHtml(titleCase(activity_type)));
@@ -243,6 +248,14 @@ function escapeHtml(text) {
   return div.innerHTML;
 }
 
+function statusBadge(active) {
+  const badge = document.createElement("span");
+  badge.className = "livetrack-badge";
+  badge.classList.toggle("livetrack-badge--live", !!active);
+  badge.textContent = active ? "Live" : "Ended";
+  return badge;
+}
+
 function summaryLabel({ session_name, activity_type, distance_meters, duration_secs }) {
   const parts = [];
   if (activity_type) parts.push(titleCase(activity_type));