feat: add device deletion endpoint with cascade cleanup and admin UI integration

Add DELETE /admin/devices/{id} endpoint with cascade deletion of device records, WireGuard peers, IP allocations, and device access profile settings. Update device status to 'deleted' and set deleted_at timestamp while preserving revoked_at if already set.

Add deleteDevice API method and delete button to devices page with query invalidation for both devices and device-profile lists. Record admin.device.deleted audit

admin-web/src/api/client.ts

@@ -225,6 +225,10 @@ export const api = {
       method: "POST",
       body: JSON.stringify({})
     }),
+  deleteDevice: (deviceId: string) =>
+    request<{ ok: boolean }>(`/admin/devices/${deviceId}`, {
+      method: "DELETE"
+    }),
   rotateDevice: (deviceId: string) =>
     request<{ ok: boolean }>(`/admin/devices/${deviceId}/rotate`, {
       method: "POST",

admin-web/src/features/devices/DevicesPage.tsx

@@ -46,6 +46,13 @@ export function DevicesPage() {
     mutationFn: api.revokeDevice,
     onSuccess: () => void queryClient.invalidateQueries({ queryKey: ["devices"] })
   });
+  const deleteMutation = useMutation({
+    mutationFn: api.deleteDevice,
+    onSuccess: () => {
+      void queryClient.invalidateQueries({ queryKey: ["devices"] });
+      void queryClient.invalidateQueries({ queryKey: ["device-profile"] });
+    }
+  });
   const rotateMutation = useMutation({
     mutationFn: api.rotateDevice,
     onSuccess: () => void queryClient.invalidateQueries({ queryKey: ["devices"] })
@@ -85,6 +92,7 @@ export function DevicesPage() {
             <div className="action-row">
               <button className="button" onClick={() => rotateMutation.mutate(rows[0].id)}>Rotate profile</button>
               <button className="ghost-button" onClick={() => revokeMutation.mutate(rows[0].id)}>Revoke device</button>
+              <button className="ghost-button" onClick={() => deleteMutation.mutate(rows[0].id)}>Delete device</button>
             </div>
           </div>
         </div>