Rework device type view to group by deviceType tag

- /api/devices now groups hosts by deviceType tag instead of host group;
  hosts without the tag are skipped
- /api/detail device lookup filters by deviceType tag instead of groupid
- getTag() is now case-insensitive on the tag name
- Removed selectHostGroups from fetchKFCData (no longer needed)
- Frontend: hex id and Zabbix deep-link use deviceType instead of groupid
- Smaller hex label (1.2rem) for device type view via hex-item--device class
- Skip DOM re-render on auto-refresh when data is unchanged (lastDataKey diff)

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

server.js

@@ -29,7 +29,8 @@ async function zabbix(method, params) {
 // ── Helpers ───────────────────────────────────────────────────────────────────
 
 function getTag(tags, name) {
-  const t = tags.find(t => t.tag === name);
+  const lower = name.toLowerCase();
+  const t = tags.find(t => t.tag.toLowerCase() === lower);
   return t ? t.value : null;
 }
 
@@ -48,10 +49,9 @@ function problemCount(triggers) {
 
 async function fetchKFCData() {
   const hosts = await zabbix('host.get', {
-    output:       ['hostid', 'host', 'name'],
-    tags:         [{ tag: 'customer', value: CUSTOMER_TAG_VALUE, operator: '1' }],
-    selectTags:   'extend',
-    selectHostGroups: ['groupid', 'name'],
+    output:     ['hostid', 'host', 'name'],
+    tags:       [{ tag: 'customer', value: CUSTOMER_TAG_VALUE, operator: '1' }],
+    selectTags: 'extend',
   });
 
   if (hosts.length === 0) return { hosts: [], triggersByHost: {} };
@@ -158,22 +158,20 @@ app.get('/api/restaurants', async (req, res) => {
 
 app.get('/api/devices', async (req, res) => {
   try {
-    const country = req.query.country || '';
     const { hosts, triggersByHost } = await fetchKFCData();
 
     const map = {};
     for (const host of hosts) {
       const hostCountry = getTag(host.tags, COUNTRY_TAG);
-      if (country && hostCountry && hostCountry.toLowerCase() !== country.toLowerCase()) continue;
+      const deviceType  = getTag(host.tags, 'deviceType');
+      if (!deviceType) continue;
 
-      for (const group of host.hostgroups) {
-        const key = `${group.groupid}__${hostCountry || ''}`;
-        if (!map[key]) {
-          map[key] = { groupid: group.groupid, name: group.name, country: hostCountry, hosts: [], triggers: [] };
-        }
-        map[key].hosts.push(host);
-        map[key].triggers.push(...(triggersByHost[host.hostid] || []));
+      const key = `${deviceType}__${hostCountry || ''}`;
+      if (!map[key]) {
+        map[key] = { deviceType, name: deviceType, country: hostCountry, hosts: [], triggers: [] };
       }
+      map[key].hosts.push(host);
+      map[key].triggers.push(...(triggersByHost[host.hostid] || []));
     }
 
     const result = Object.values(map)
@@ -193,7 +191,7 @@ app.get('/api/devices', async (req, res) => {
         }
         problems.sort((a, b) => b.priority - a.priority || b.lastchange - a.lastchange);
         return {
-          groupid:      g.groupid,
+          deviceType:   g.deviceType,
           name:         g.name,
           country:      g.country,
           hostCount:    g.hosts.length,
@@ -220,7 +218,7 @@ app.get('/api/detail', async (req, res) => {
 
     const filtered = type === 'restaurant'
       ? hosts.filter(h => getTag(h.tags, 'location') === id)
-      : hosts.filter(h => h.hostgroups.some(g => g.groupid === id));
+      : hosts.filter(h => getTag(h.tags, 'deviceType') === id);
 
     const items = filtered.map(host => ({
       hostid:   host.hostid,