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-phase3-runtime.sh

@@ -77,54 +77,74 @@ run_qemu_checks() {
         exit 2
     }
 
-    local arch image extra
+    local arch image iso extra
     arch="${ARCH:-$(uname -m)}"
     image="build/$arch/$config/harddrive.img"
+    iso="build/$arch/$config.iso"
     extra="build/$arch/$config/extra.img"
 
-    if [[ ! -f "$image" ]]; then
-        echo "ERROR: missing image $image" >&2
+    boot_media=""
+    if [[ -f "$iso" ]]; then
+        boot_media="iso"
+    elif [[ -f "$image" ]]; then
+        boot_media="harddrive"
+    else
+        echo "ERROR: no bootable image found ($iso or $image)" >&2
         echo "Build it first with: ./local/scripts/build-redbear.sh $config" >&2
         exit 2
     fi
 
+    if [[ "$boot_media" == "iso" ]]; then
+        boot_args=(-cdrom "$iso")
+    else
+        boot_args=(-drive file="$image",format=raw,if=none,id=drv0,snapshot=on -device nvme,drive=drv0,serial=NVME_SERIAL)
+    fi
+
     if [[ ! -f "$extra" ]]; then
         truncate -s 1g "$extra"
     fi
 
-    expect <<EXPECT_SCRIPT
-log_user 1
-set timeout 300
-spawn qemu-system-x86_64 -name {Red Bear OS x86_64} -device qemu-xhci -smp 4 -m 2048 -bios $firmware -chardev stdio,id=debug,signal=off,mux=on -serial chardev:debug -mon chardev=debug -machine q35 -device ich9-intel-hda -device hda-output -device virtio-net,netdev=net0 -netdev user,id=net0 -nographic -vga none -drive file=$image,format=raw,if=none,id=drv0 -device nvme,drive=drv0,serial=NVME_SERIAL -drive file=$extra,format=raw,if=none,id=drv1 -device nvme,drive=drv1,serial=NVME_EXTRA -enable-kvm -cpu host
-expect "login:"
-send "root\r"
-expect "assword:"
-send "password\r"
-expect "Type 'help' for available commands."
-send "echo __READY__\r"
-expect "__READY__"
-
-send "command -v redbear-phase3-kwin-check >/dev/null 2>&1 && echo __PHASE3_BIN_OK__ || echo __PHASE3_BIN_FAIL__\r"
-expect {
-    "__PHASE3_BIN_OK__" { }
-    "__PHASE3_BIN_FAIL__" { puts "FAIL: redbear-phase3-kwin-check is missing"; exit 1 }
-    timeout { puts "FAIL: timed out while checking for redbear-phase3-kwin-check"; exit 1 }
-    eof { puts "FAIL: guest exited before Phase 3 binary check completed"; exit 1 }
-}
-
-send "redbear-phase3-kwin-check --json >/dev/null 2>&1 && echo __PHASE3_OK__ || echo __PHASE3_FAIL__\r"
-expect {
-    "__PHASE3_OK__" { }
-    "__PHASE3_FAIL__" { puts "FAIL: redbear-phase3-kwin-check reported failures"; exit 1 }
-    timeout { puts "FAIL: timed out while running redbear-phase3-kwin-check"; exit 1 }
-    eof { puts "FAIL: guest exited before Phase 3 check completed"; exit 1 }
-}
-
-send "echo __PHASE3_RUNTIME_DONE__\r"
-expect "__PHASE3_RUNTIME_DONE__"
-send "shutdown\r"
-expect eof
-EXPECT_SCRIPT
+    attempt=1
+    while true; do
+        rc=0
+        python3 local/scripts/qemu-login-expect.py \
+            --timeout 300 \
+            --log "build/$arch/$config/phase3-check.log" \
+            --step "expect:login:" \
+            --step "send:root" \
+            --step "expect:assword:" \
+            --step "send:password" \
+            --step "expect:Type 'help' for available commands." \
+            --step "send:echo __READY__" \
+            --step "expect:__READY__" \
+            --step "send:command -v redbear-phase3-kwin-check >/dev/null 2>&1 && echo __PHASE3_BIN_OK__ || echo __PHASE3_BIN_FAIL__" \
+            --step "expect:__PHASE3_BIN_OK__" \
+            --step "send:redbear-phase3-kwin-check --json >/dev/null 2>&1 && echo __PHASE3_OK__ || echo __PHASE3_FAIL__" \
+            --step "expect:__PHASE3_OK__" \
+            --step "send:echo __PHASE3_RUNTIME_DONE__" \
+            --step "expect:__PHASE3_RUNTIME_DONE__" \
+            --step "send:shutdown" \
+            --pass_marker "__PHASE3_BIN_OK__" \
+            --pass_marker "__PHASE3_OK__" \
+            --pass_marker "__PHASE3_RUNTIME_DONE__" \
+            --fail_marker "__PHASE3_BIN_FAIL__" \
+            --fail_marker "__PHASE3_FAIL__" \
+            -- \
+            qemu-system-x86_64 -name "Red Bear OS x86_64" -device qemu-xhci -smp 4 -m 2048 -bios "$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 -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 || 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
+    pkill -f "qemu-system-x86_64.*$config" 2>/dev/null || true
+    echo "Phase 3 desktop session preflight completed via guest runtime check"
+    exit 0
 }
 
 usage() {