Stabilize live ISO consoles and NVIDIA boot path

iso/overlay/usr/local/bin/bee-log-run

@@ -0,0 +1,29 @@
+#!/bin/bash
+# bee-log-run — run a command, append its output to a file, and keep stdout/stderr
+# connected to systemd so journald and the serial console also receive the logs.
+
+set -o pipefail
+
+log_file="$1"
+shift
+
+if [ -z "$log_file" ] || [ "$#" -eq 0 ]; then
+    echo "usage: $0 <log-file> <command> [args...]" >&2
+    exit 2
+fi
+
+mkdir -p "$(dirname "$log_file")"
+
+serial_sink() {
+    local tty="$1"
+    if [ -w "$tty" ]; then
+        cat > "$tty"
+    else
+        cat > /dev/null
+    fi
+}
+
+"$@" 2>&1 | tee -a "$log_file" \
+    >(serial_sink /dev/ttyS0) \
+    >(serial_sink /dev/ttyS1)
+exit "${PIPESTATUS[0]}"