List rows click through to the item; drop the redundant VLANs tab

Row-click: the whole table row now navigates to the item detail (machines, PCs,
printers, network devices, measuring tools, applications), matching the Networks
list. The actions cell is @click.stop so View/Edit/Delete still work
independently; a shared .clickable-row style gives the cursor + hover.

Network hub: drop the VLANs tab - a subnet belongs to a VLAN (each Networks row
already shows its VLAN) so a sibling tab was redundant; VLAN naming stays in
Settings. Hub is now Devices | Networks.

Verified: row-click navigates on machines/pcs/network; hub shows two tabs.

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

frontend/src/assets/style.css

@@ -1742,3 +1742,9 @@ td.actions {
   color: var(--text-light);
   cursor: pointer;
 }
+
+/* Clickable list rows: the whole row navigates to the item detail; interactive
+   cells (the actions column, in-row links) stop propagation so they still work
+   independently. */
+.clickable-row { cursor: pointer; }
+.clickable-row:hover td { background: var(--bg); }