fix(webinstaller): point users at http://<hostname>.local after reboot

The post-reboot page told users to log in with the username and
password — but Furtka is browser-first; users aren't meant to touch
the TTY. Show the actual URL they should open instead, plus an mDNS
fallback hint.

Also pin the header SVG to width="24" height="24" so it can never
render at full viewport size, even if CSS somehow fails to load.
Belt-and-suspenders with the reboot-delay fix.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

webinstaller/app.py

@@ -639,7 +639,7 @@ def install_reboot():
         ["/bin/sh", "-c", "sleep 3 && /usr/bin/systemctl reboot"],
         start_new_session=True,
     )
-    return render_template("install/rebooting.html")
+    return render_template("install/rebooting.html", hostname=settings["hostname"])
 
 
 if __name__ == "__main__":

webinstaller/static/style.css

@@ -126,6 +126,10 @@ h1 {
   margin: 0 0 2rem;
   font-size: 1.05rem;
 }
+.muted {
+  color: var(--fg-muted);
+  font-size: 0.9rem;
+}
 
 /* ── Forms ──────────────────────────────────────────────────── */
 

webinstaller/templates/base.html

@@ -11,7 +11,7 @@
     <header class="site-header">
         <div class="container">
             <a href="{{ url_for('install_step_1') }}" class="site-title" aria-label="Furtka Installer — restart">
-                <svg class="gate-mark" viewBox="0 0 24 24" fill="none" stroke="currentColor"
+                <svg class="gate-mark" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor"
                      stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
                     <path d="M4 20 V12 A9 9 0 0 1 20 12 V20"/>
                     <line x1="12" y1="5" x2="12" y2="20"/>

webinstaller/templates/install/rebooting.html

@@ -6,5 +6,7 @@
 {% block content %}
 <h1>Rebooting…</h1>
 <p class="lede">The machine is restarting. This page will stop responding in a moment — that's expected.</p>
-<p>When the machine comes back up, log in with the username and password you set during the install.</p>
+<p>When the machine comes back up (~1 minute), open Furtka in your browser:</p>
+<p><a href="http://{{ hostname }}.local" class="btn btn-primary">http://{{ hostname }}.local</a></p>
+<p class="muted">If that doesn't resolve, your network may not support mDNS — use the IP address shown on the machine's console instead.</p>
 {% endblock %}