Network: consolidate into one tabbed hub; subnet devices span all asset types

Replaces the two flat "Network Devices" + "View Networks" nav entries with a
single "Network" entry opening a tabbed hub: Devices | Networks | VLANs
(NetworkHub renders the existing device list, the subnet browse, and the VLAN
list; VLANs is now reachable outside Settings). /network -> hub; /networks
redirects to the Networks tab; subnet detail stays at /networks/:id.

Subnet "Devices on this network" now matches ANY asset whose primary IP falls in
the CIDR (PCs, printers, machines, measuring tools - not just network devices),
computed on the core Communication + Asset tables; each row links to its typed
detail (extension id resolved lazily/guarded per plugin). Fixes the empty list -
printers and PCs carry IPs and now appear (e.g. 35 devices on 10.80.92.0/24).

Also: subnet-browse search uses the standard form-control styling; dropped the
redundant per-tab page header.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/views/network/SubnetDetail.vue

@@ -37,14 +37,13 @@
                   <tr><th>Device</th><th>IP</th><th>Type</th></tr>
                 </thead>
                 <tbody>
-                  <tr v-for="dev in devices" :key="dev.networkdeviceid">
+                  <tr v-for="dev in devices" :key="dev.assetid">
                     <td>
-                      <router-link :to="`/network/${dev.networkdeviceid}`">
-                        {{ dev.name || dev.hostname || dev.assetnumber }}
-                      </router-link>
+                      <router-link v-if="dev.url" :to="dev.url">{{ dev.name || dev.assetnumber }}</router-link>
+                      <span v-else>{{ dev.name || dev.assetnumber }}</span>
                     </td>
                     <td class="mono">{{ dev.ipaddress }}</td>
-                    <td>{{ dev.networkdevicetypename || '-' }}</td>
+                    <td>{{ typeLabel(dev.assettype) }}</td>
                   </tr>
                 </tbody>
               </table>
@@ -67,6 +66,14 @@ const loading = ref(true)
 
 const devices = computed(() => subnet.value?.devices || [])
 
+const TYPE_LABELS = {
+  computer: 'PC', network_device: 'Network Device', printer: 'Printer',
+  machine: 'Machine', measuring_tool: 'Measuring Tool',
+}
+function typeLabel(type) {
+  return TYPE_LABELS[type] || type || '-'
+}
+
 async function load() {
   loading.value = true
   try {