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>

phobos-panel.service

@@ -6,7 +6,7 @@ Wants=wg-quick@wg0.service
 [Service]
 Type=simple
 WorkingDirectory=/opt/phobos-panel
-ExecStart=/usr/bin/gunicorn -w 1 -b 0.0.0.0:8443 app:app
+ExecStart=/usr/bin/gunicorn -w 1 --threads 20 -b 0.0.0.0:8443 app:app
 Restart=always
 RestartSec=5
 Environment=PYTHONUNBUFFERED=1