Fix empty-object false negative in links page no-data check

The check `!data.hosts && !data.unifi_switches` never caught empty
objects `{}`, which are truthy. Replace with Object.keys length checks
so the friendly "no data yet" banner renders when both collections
are empty.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

diagnose.py

@@ -78,7 +78,7 @@ class DiagnosticsRunner:
             f'ssh -o StrictHostKeyChecking=accept-new -o ConnectTimeout=5 '
             f'-o BatchMode=yes -o LogLevel=ERROR '
             f'-o ServerAliveInterval=10 -o ServerAliveCountMax=2 '
-            f'root@{ip_q} \'{remote_cmd}\''
+            f'root@{ip_q} {shlex.quote(remote_cmd)}'
         )
 
     # ------------------------------------------------------------------

static/app.js

@@ -220,7 +220,7 @@ function updateEventsTable(events, totalActive) {
       ? GANDALF_CONFIG.ticket_web_url : 'http://t.lotusguild.org/ticket/';
     const ticket = e.ticket_id
       ? `<a href="${lt.escHtml(ticketBase)}${lt.escHtml(String(e.ticket_id))}" target="_blank"
-            class="ticket-link">#${e.ticket_id}</a>`
+            class="ticket-link">#${lt.escHtml(String(e.ticket_id))}</a>`
       : '–';
     const supBadge = e.is_suppressed
       ? `<span class="lt-badge badge-suppressed" title="Alert suppressed">🔕 sup</span>`

templates/links.html

@@ -548,7 +548,7 @@ function checkLinksStale(updatedStr) {
 async function loadLinks() {
   try {
     const data = await lt.api.get('/api/links');
-    if (!data.hosts && !data.unifi_switches) {
+    if ((!data.hosts || !Object.keys(data.hosts).length) && (!data.unifi_switches || !Object.keys(data.unifi_switches).length)) {
       document.getElementById('links-container').innerHTML =
         '<div class="link-no-data">No link data yet — monitor has not completed a full cycle.</div>';
       return;