Replace from-scratch rewrite with real ngoduykhanh/wireguard-ui fork

The from-scratch Go rewrite had unresolved bugs (missing go.sum, UI
404s, path issues) from being built without a working local Go
toolchain to verify against. Switching strategy: use the actual
upstream wireguard-ui codebase (proven, battle-tested single-server
manager) as the base, and extend it for multi-server support instead
of re-deriving everything from zero.

Kept our own installers (bootstrap.sh, update.sh, scripts/install.sh,
scripts/proxmox-install.sh) - these still apply, just need updating
to build/install the upstream module layout instead of the old
cmd/wireguard-ui-multi structure.

Module path intentionally left as upstream's own
(github.com/ngoduykhanh/wireguard-ui) for now to avoid touching every
internal import; revisit if this needs to be fully rebranded.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

init.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+# extract wg config file path, or use default
+conf="$(jq -r .config_file_path db/server/global_settings.json || echo /etc/wireguard/wg0.conf)"
+
+# manage wireguard stop/start with the container
+case $WGUI_MANAGE_START in (1|t|T|true|True|TRUE)
+    wg-quick up "$conf"
+    trap 'wg-quick down "$conf"' SIGTERM # catches container stop
+esac
+
+# manage wireguard restarts
+case $WGUI_MANAGE_RESTART in (1|t|T|true|True|TRUE)
+    [[ -f $conf ]] || touch "$conf" # inotifyd needs file to exist
+    inotifyd - "$conf":w | while read -r event file; do
+        wg-quick down "$file"
+        wg-quick up "$file"
+    done &
+esac
+
+
+./wg-ui &
+wait $!