fix(rotate): don't skip when only PPSKs are flagged; move webhooks under /settings

* Password rotation was short-circuiting any run that had no whole-SSID
  wlan_ids configured, even if there were PPSKs with rotate_password=true
  in the database. The PPSK rotation block lived after the early-return,
  so per-PPSK rotation never fired. Now we only skip when there's nothing
  at all to rotate (neither wlan_ids nor PPSK opt-ins).
* Webhook routes moved from /app/network/webhooks to
  /app/network/settings/webhooks so the URL reflects that this is a
  settings tab. Route names unchanged.

v1.5.3.

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": "1.5.2",
+    "version": "1.5.3",
     "type": "library",
     "license": "MIT",
     "autoload": {