Publish DHCP clients' names in DNS

router-webui leases-dns reads Kea's leases and publishes <name>.<domain>
with reverse records in the running Unbound (router.dns.dynamicLeases).
Names the configuration publishes are never taken over; a client's name
is cut to its first label and kept inside the local domain; of two
clients the newer lease wins. The DNS page switches it on and shows what
is published and what was skipped; router-setup enables it with a domain.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AeFqV9dZrK6nipHkPfyM4F

pkgs/router-webui/templates/dns.html

@@ -42,9 +42,41 @@
     </table>
     <p class="hint">Names below these domains are asked from these resolvers (for example across a tunnel), not from the internet.</p>
   </fieldset>
+
+  <fieldset>
+    <legend>DHCP clients</legend>
+    <label><input type="checkbox" name="dynamic" {{if .Dynamic}}checked{{end}}> Publish the names of DHCP clients as <code>name.{{if .Domain}}{{.Domain}}{{else}}domain{{end}}</code></label>
+    {{if and .Dynamic (not .Domain)}}<p class="field-error">This needs a local domain (Network page).</p>{{end}}
+    <p class="hint">A client chooses its own name, so only its first label is used, only in your local domain, and a name
+       that is configured here (a record above, a reservation, the router itself, a wildcard) is never taken over.
+       Of two clients with one name the newer lease wins. Takes effect when applied.</p>
+  </fieldset>
   <button>Save</button>
 </form>
 
+{{if .Dyn}}
+<section>
+  <h2>DHCP clients in DNS</h2>
+  {{if .Dyn.Error}}<p class="field-error">The last update failed: {{.Dyn.Error}}</p>{{end}}
+  {{if .Dyn.Published}}
+  <table>
+    <tr><th>Name</th><th>Address</th></tr>
+    {{range .Dyn.Published}}<tr><td>{{.Name}}</td><td>{{.Address}}</td></tr>{{end}}
+  </table>
+  {{else}}<p class="muted">No client names are published at the moment.</p>{{end}}
+  {{if .Dyn.Skipped}}
+  <p class="hint">Not published:</p>
+  <table>
+    <tr><th>Client name</th><th>Address</th><th>Why</th></tr>
+    {{range .Dyn.Skipped}}<tr><td>{{.Hostname}}</td><td>{{.Address}}</td><td>{{.Reason}}</td></tr>{{end}}
+  </table>
+  {{end}}
+  <p class="hint">As of {{ago .Dyn.Updated}} ago, from the running configuration.</p>
+</section>
+{{else if .Dynamic}}
+<p class="hint">Client names are not published yet: apply the settings so the service starts.</p>
+{{end}}
+
 {{if .Auto}}
 <section>
   <h2>Published automatically</h2>