fix(reboot): reject unknown uptime as fresh boot

scripts/reboot-recovery/tests/test_reboot_event_detector.py

@@ -110,3 +110,63 @@ def test_reboot_detector_fails_visible_when_windows_or_vm_host_missing(tmp_path:
     assert "99" in payload["missing_hosts"]
     assert payload["all_required_hosts_observed"] is False
     assert payload["all_required_hosts_in_reboot_window"] is False
+
+
+def test_reboot_detector_does_not_treat_unknown_uptime_as_fresh_boot(
+    tmp_path: Path,
+) -> None:
+    probe_path = tmp_path / "host-probe.txt"
+    state_path = tmp_path / "state.json"
+    output_path = tmp_path / "event.json"
+    probe_path.write_text(
+        "\n".join(
+            [
+                "AWOOOI_REBOOT_AUTO_RECOVERY_HOST_PROBE=1",
+                "TARGET_HOSTS=99",
+                (
+                    "HOST_BOOT alias=99 target=192.168.0.99 "
+                    "startup_unit=vmware-host-autostart reachable=1 "
+                    "boot_id=reachable_unknown_boot uptime_seconds=unknown "
+                    "systemd_state=ping_reachable startup_enabled=unknown "
+                    "startup_active=unknown"
+                ),
+            ]
+        )
+        + "\n",
+        encoding="utf-8",
+    )
+    state_path.write_text(
+        json.dumps({"hosts": {"99": {"boot_id": "win-boot-1"}}}),
+        encoding="utf-8",
+    )
+
+    subprocess.run(
+        [
+            sys.executable,
+            str(SCRIPT),
+            "--host-probe-file",
+            str(probe_path),
+            "--state-file",
+            str(state_path),
+            "--target-minutes",
+            "10",
+            "--generated-at",
+            "2026-06-30T18:00:00+08:00",
+            "--output",
+            str(output_path),
+            "--required-host",
+            "99",
+            "--no-write-state",
+        ],
+        check=True,
+    )
+
+    payload = json.loads(output_path.read_text(encoding="utf-8"))
+
+    assert payload["observed_hosts"] == ["99"]
+    assert payload["reboot_detected"] is False
+    assert payload["fresh_boot_hosts"] == []
+    assert payload["rebooted_hosts"] == []
+    assert payload["all_required_hosts_observed"] is True
+    assert payload["all_required_hosts_in_reboot_window"] is False
+    assert payload["state_written"] is False