release: 1.4.0 — one version for stable/beta/dev

Light/dark theme and compact mobile layout, per-client speed limit, real
speed tests, panel domain (Let's Encrypt), client address + cascade relay,
RKN scanner guard, WARP, backup/restore, router web terminal, Android VPN
client with split tunnelling and Android admin app. Updating from 1.2.x
keeps keys, server.env and clients; tested 1.2.8 -> 1.4.0 on live VMs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android-client/res/values/styles.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <style name="AppTheme" parent="android:Theme.Material.Light.NoActionBar">
+        <item name="android:colorPrimary">#4338ca</item>
+        <item name="android:colorPrimaryDark">#1e1b4b</item>
+        <item name="android:colorAccent">#4f46e5</item>
+        <item name="android:windowBackground">#f1f5f9</item>
+        <item name="android:statusBarColor">#1e1b4b</item>
+    </style>
+</resources>