Add web GUI, docs, scripts, and 5G router config

- Web app (Flask): status, config, firewall, logs, users, restart
- Docs: AT commands, deploy, DNS, quickstart, web GUI
- Scripts: connect, deploy, diag, healthcheck, modem-status, speedtest, status, troubleshoot
- Init and iptables: 5g-router, 5g-webgui, rules.v4
- CHANGELOG, TODO, REVISION; config and README updates

web/templates/restart.html

@@ -0,0 +1,8 @@
+{% extends "base.html" %}
+{% block title %}Restart 5G – Alpine 5G Router{% endblock %}
+{% block content %}
+<h2>Restart 5G connection</h2>
+<p style="color: var(--text-muted); margin: 0 0 1rem;">Run the connection script to bring up or refresh the 5G link.</p>
+<button type="button" class="btn btn-primary" id="restart5gBtn">Restart 5G</button>
+<div id="restartMsg" class="msg"></div>
+{% endblock %}