cisco-vpn: Strip ANSI color codes from log file

apps/rego-tunnel/shared/cisco-vpn

@@ -70,8 +70,11 @@ log() {
     local timestamp_short=$(date '+%H:%M:%S')
     local log_file=$(get_log_file)
 
+    # Strip ANSI color codes for log file
+    local msg_plain=$(echo -e "$msg" | sed 's/\x1b\[[0-9;]*m//g')
+
     # Write to log file (plain text, no colors)
-    echo "[$timestamp] [$level] $msg" >> "$log_file"
+    echo "[$timestamp] [$level] $msg_plain" >> "$log_file"
 
     # Write to console (with colors)
     case $level in