tests: replace expect with stdlib python helper for QEMU login proofs

Drop the host expect dependency from the PS/2, timer, IOMMU, and USB
storage (BOT) runtime proofs. local/scripts/qemu-login-expect.py drives
the guest over serial-on-stdio with ordered expect/send steps, per-step
timeouts (matching expect's per-pattern semantics), and pass/fail markers.
It distinguishes premature QEMU death (exit 3) from genuine check failure
(exit 1) so the scripts retry external interruptions without retrying real
failures. Scripts use headless -display none -vga none (fbcond serial
mirror), a 3600s per-step timeout, and a retry loop (max 5 attempts).

local/scripts/test-ps2-qemu.sh

@@ -93,23 +93,37 @@ pkill -f "qemu-system-x86_64.*$config" 2>/dev/null || true
 sleep 1
 
 if [[ "$check_mode" -eq 1 ]]; then
-    expect <<EOF
-log_user 1
-set timeout 240
-spawn qemu-system-x86_64 -name {Red Bear OS x86_64} -device qemu-xhci -smp 4 -m 2048 -bios $firmware -chardev stdio,id=debug,signal=off,mux=on -serial chardev:debug -mon chardev=debug -machine q35 -device ich9-intel-hda -device hda-output -device virtio-net,netdev=net0 -netdev user,id=net0 -object filter-dump,id=f1,netdev=net0,file=build/$arch/$config/network.pcap -nographic -vga none ${boot_args[*]} -drive file=$extra,format=raw,if=none,id=drv1,snapshot=on -device nvme,drive=drv1,serial=NVME_EXTRA -enable-kvm -cpu host $extra_qemu_args
-expect "login:"
-send "root\r"
-expect "assword:"
-send "password\r"
-expect "Type 'help' for available commands."
-send "redbear-phase-ps2-check\r"
-expect "Red Bear OS PS/2 Runtime Check"
-expect "present=/scheme/serio/0"
-expect "present=/scheme/serio/1"
-expect "phase3_input_check=ok"
-send "shutdown\r"
-sleep 2
-EOF
+    attempt=1
+    while true; do
+        rc=0
+        python3 local/scripts/qemu-login-expect.py \
+        --timeout 3600 \
+        --log "build/$arch/$config/ps2-check.log" \
+        --step "expect:login:" \
+        --step "send:root" \
+        --step "expect:assword:" \
+        --step "send:password" \
+        --step "expect:Type 'help' for available commands." \
+        --step "send:redbear-phase-ps2-check" \
+        --step "expect:Red Bear OS PS/2 Runtime Check" \
+        --step "expect:present=/scheme/serio/0" \
+        --step "expect:present=/scheme/serio/1" \
+        --step "expect:phase3_input_check=ok" \
+        --step "send:shutdown" \
+        --pass_marker "phase3_input_check=ok" \
+        -- \
+        qemu-system-x86_64 -name "Red Bear OS x86_64" -device qemu-xhci -smp 4 -m 2048 -bios "$firmware" -chardev stdio,id=debug,signal=off,mux=on -serial chardev:debug -mon chardev=debug -machine q35 -device ich9-intel-hda -device hda-output -device virtio-net,netdev=net0 -netdev user,id=net0 -object filter-dump,id=f1,netdev=net0,file="build/$arch/$config/network.pcap" -display none -vga none "${boot_args[@]}" -drive file="$extra",format=raw,if=none,id=drv1,snapshot=on -device nvme,drive=drv1,serial=NVME_EXTRA -enable-kvm -cpu host $extra_qemu_args || rc=$?
+        if [[ $rc -eq 0 ]]; then
+            break
+        fi
+        if [[ ( $rc -eq 3 || $rc -eq 137 ) && $attempt -lt 5 ]]; then
+            attempt=$((attempt + 1))
+            echo "QEMU exited before completing the check; retrying (attempt $attempt/3)"
+            sleep 2
+            continue
+        fi
+        exit "$rc"
+    done
     pkill -f "qemu-system-x86_64.*$image" 2>/dev/null || true
     echo "PS/2 serio runtime validation completed via guest runtime check"
     exit 0
@@ -129,9 +143,8 @@ exec qemu-system-x86_64 \
   -device virtio-net,netdev=net0 \
   -netdev user,id=net0 \
   -object filter-dump,id=f1,netdev=net0,file="build/$arch/$config/network.pcap" \
-  -nographic -vga none \
-  -drive file="$image",format=raw,if=none,id=drv0,snapshot=on \
-  -device nvme,drive=drv0,serial=NVME_SERIAL \
+  -display none -vga none \
+  "${boot_args[@]}" \
   -drive file="$extra",format=raw,if=none,id=drv1,snapshot=on \
   -device nvme,drive=drv1,serial=NVME_EXTRA \
   -enable-kvm -cpu host \