chore(nav): drop Webhooks nav row — moved into Settings tabs

Webhooks now lives as a tab alongside Connection / Tasks / Logs /
Access in the Settings page. The standalone Webhooks page still
exists at /app/network/webhooks but no longer appears in the sidebar.

v1.5.1.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

composer.json

@@ -1,7 +1,7 @@
 {
     "name": "dashboard/unifi",
     "description": "UniFi network management, WiFi stats, and captive portal authentication for the Dashboard platform",
-    "version": "1.5.0",
+    "version": "1.5.1",
     "type": "library",
     "license": "MIT",
     "autoload": {
@@ -28,7 +28,6 @@
                 { "label": "Clients",          "route_name": "unifi.clients",          "icon": "users",            "permission": "unifi.stats",    "sort_order": 4 },
                 { "label": "WiFi Networks",    "route_name": "unifi.wifi",             "icon": "wifi",             "permission": "unifi.manage",   "sort_order": 5 },
                 { "label": "Portal",           "route_name": "unifi.portal.settings",  "icon": "shield-check",     "permission": "unifi.auth",     "sort_order": 6 },
-                { "label": "Webhooks",         "route_name": "unifi.webhooks.index",   "icon": "bell-alert",       "permission": "unifi.settings", "sort_order": 7 },
                 { "label": "Settings",         "route_name": "unifi.settings",         "icon": "cog-6-tooth",      "permission": "unifi.settings", "sort_order": 99 }
             ],
             "permissions": [