feat: installer fetched from the direct address sets it as the agent's own with the main one as fallback (and downloads from it); agents fall back to whichever address is not theirs; (direct) beside the connection status

internal/server/web/templates/edit.html

@@ -76,7 +76,7 @@
   <div class="card">
     <h2>Связь с сервером</h2>
     <p class="muted">
-      Сейчас: {{if not .Online}}<span>офлайн</span>{{else if .OnWS}}<span style="color:var(--ok)">WebSocket</span>{{else}}<span>long polling</span>{{end}}
+      Сейчас: {{if not .Online}}<span>офлайн</span>{{else if .OnWS}}<span style="color:var(--ok)">WebSocket</span>{{else}}<span>long polling</span>{{end}}{{if and .Online .ViaDirect}} <span class="muted">(direct)</span>{{end}}
     </p>
     <form method="post" action="/agents/{{.Agent.ID}}/transport" class="row">
       <input type="hidden" name="csrf" value="{{.CSRF}}">