tests: migrate remaining QEMU runtime proofs to qemu-login-expect.py

Convert the remaining expect-based test scripts (phase1-6 runtime, usb,
wifi, bluetooth, dbus, greeter, live-iso, posix) to the stdlib python
harness, completing the migration started in 9ec00d4c81. Each script now
prefers booting the live ISO when present (falling back to harddrive.img
with snapshot=on), and retries up to 5 times when QEMU exits early or is
killed (rc 3 / 137) — the host-contention failure mode recorded in the
2026-07-20 runtime-proof status.

qemu-login-expect.py: treat an incomplete step sequence as a failure even
when a pass marker was seen partway through — partial sequences must not
count as a pass.

local/scripts/test-phase5-gpu-runtime.sh

@@ -56,22 +56,53 @@ run_guest_checks() {
 
 run_qemu_checks() {
     local arch="${ARCH:-x86_64}"
+    local iso="build/${arch}/${CONFIG}.iso"
     local image="build/${arch}/${CONFIG}/harddrive.img"
     local firmware="${FIRMWARE_PATH:-/usr/share/ovmf/x64/OVMF.fd}"
-    if [[ ! -f "$image" ]]; then echo "$PROG: image not found: $image (build with: make all CONFIG_NAME=$CONFIG)"; exit 1; fi
+
+    local boot_args=()
+    if [[ -f "$iso" ]]; then
+        boot_args=(-cdrom "$iso")
+    elif [[ -f "$image" ]]; then
+        boot_args=(-drive file="$image",format=raw,if=none,id=drv0,snapshot=on -device nvme,drive=drv0,serial=NVME_SERIAL)
+    else
+        echo "$PROG: no bootable image found ($iso or $image)"
+        echo "$PROG: build with: make all CONFIG_NAME=$CONFIG"
+        exit 1
+    fi
     if [[ ! -f "$firmware" ]]; then echo "$PROG: firmware not found: $firmware"; exit 1; fi
-    expect <<EXPECT_SCRIPT
-log_user 1; set timeout 300
-spawn qemu-system-x86_64 -name {Red Bear OS} -device qemu-xhci -smp 4 -m 2048 -bios $firmware -chardev stdio,id=debug,signal=off,mux=on -serial chardev:debug -mon chardev:debug -machine q35 -device virtio-net,netdev=net0 -netdev user,id=net0 -nographic -vga none -drive file=$image,format=raw,if=none,id=drv0 -device nvme,drive=drv0,serial=NVME_SERIAL -enable-kvm -cpu host
-expect "login:"; send "root\r"
-expect "assword:"; send "password\r"
-expect "Type 'help' for available commands."
-send "echo __READY__\r"; expect "__READY__"
-send "redbear-phase5-gpu-check --json >/dev/null 2>&1 && echo __P5_OK__ || echo __P5_FAIL__\r"
-expect { "__P5_OK__" { } "__P5_FAIL__" { puts "FAIL: Phase 5"; exit 1 } timeout { puts "FAIL: timeout"; exit 1 } eof { puts "FAIL: eof"; exit 1 } }
-puts "ALL PHASE 5 CHECKS PASSED"
-EXPECT_SCRIPT
-    exit $?
+
+    attempt=1
+    while true; do
+        rc=0
+        python3 local/scripts/qemu-login-expect.py \
+            --timeout 300 \
+            --log "build/${arch}/${CONFIG}/phase5-gpu-check.log" \
+            --step "expect:login:" \
+            --step "send:root" \
+            --step "expect:assword:" \
+            --step "send:password" \
+            --step "expect:Type 'help' for available commands." \
+            --step "send:echo __READY__" \
+            --step "expect:__READY__" \
+            --step "send:redbear-phase5-gpu-check --json >/dev/null 2>&1 && echo __P5_OK__ || echo __P5_FAIL__" \
+            --pass_marker "__P5_OK__" \
+            --fail_marker "__P5_FAIL__" \
+            -- \
+            qemu-system-x86_64 -name "Red Bear OS" -device qemu-xhci -smp 4 -m 2048 -bios "$firmware" -chardev stdio,id=debug,signal=off,mux=on -serial chardev:debug -mon chardev:debug -machine q35 -device virtio-net,netdev=net0 -netdev user,id=net0 -nographic -vga none "${boot_args[@]}" -enable-kvm -cpu host || rc=$?
+        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 $attempt/5)"
+            sleep 2
+            continue
+        fi
+        exit "$rc"
+    done
+    echo "ALL PHASE 5 CHECKS PASSED"
+    exit 0
 }
 
 case "$MODE" in