Remove allowed_users.txt from tracking, add local/umbrel mode, UMBREL_IP support

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

entrypoint.local.sh

@@ -1,17 +1,19 @@
 #!/usr/bin/env bash
 set -e
 
+: "${UMBREL_IP:?UMBREL_IP is not set. Add it to your .env file (e.g. UMBREL_IP=192.168.1.100)}"
+
 mkdir -p /root/.electrum/wallets
 
 CONFIG="/root/.electrum/config"
 if [ ! -f "$CONFIG" ]; then
     echo "Writing default config..."
-    cat > "$CONFIG" <<'EOF'
+    cat > "$CONFIG" <<EOF
 {
     "auto_connect": false,
     "enable_proxy": false,
     "oneserver": true,
-    "server": "umbrel.local:50001:t"
+    "server": "${UMBREL_IP}:50001:t"
 }
 EOF
 fi