fix(update): the crash cells' marker oracle applies update_lock's v1 age ceiling (review F51)

What: the test's _identity_live takes the marker age and, for an identity without a creation time, is live only within hermes_cli.update_lock.UPDATE_MARKER_MAX_AGE_SECONDS.
Why: the oracle read a ct-less (v1) marker for a live pid as LIVE past the product's 20-minute ceiling, so it could disagree with the verdict update_lock gives every other updater.
Red: pre-fix test_crash_cells.py -> [1260-False-False] FAILED (6 passed, 1 failed).
Green: 7 passed, 0 failed.

tests/ci/test_windows_update_crash_oracles.py

@@ -1,9 +1,12 @@
 """The Windows crash cells' oracles, judged on this OS: a verdict the cells can only reach on a
 Windows runner must still say pass exactly when the user's update was what the cell claims."""
 
+import os
 import subprocess
+import time
 from pathlib import Path
 
+import psutil
 import pytest
 
 import tests.e2e.core.windows_update.test_crash_cells as crash
@@ -57,3 +60,15 @@ def test_kill_point_counts_only_an_update_killed_while_running(
     else:
         with pytest.raises(AssertionError, match="cell: the update"):
             crash._kill_when(_Machine(tmp_path), proc, "cell", point, "t")
+
+
+@pytest.mark.parametrize("age,with_ct,live", [
+    (60, False, True),  # v1 marker inside update_lock's 20-minute ceiling
+    (1260, False, False),  # v1 past the ceiling: the product reads it DEAD (the pid may be reused)
+    (1260, True, True),  # a matching creation time is live at any age
+])
+def test_marker_oracle_reads_a_marker_live_exactly_when_update_lock_does(age, with_ct, live):
+    pid = os.getpid()
+    ct = f"ct:{psutil.Process(pid).create_time():.3f}\n" if with_ct else ""
+    text = f"{pid}\n{time.time() - age}\n{ct}"
+    assert crash._marker_live(text) == (f"owner {pid}" if live else None)

tests/e2e/core/windows_update/test_crash_cells.py

@@ -67,6 +67,7 @@ from pathlib import Path
 import psutil
 import pytest
 
+from hermes_cli.update_lock import UPDATE_MARKER_MAX_AGE_SECONDS
 from tests.e2e.core._pending_fixes import known_failure
 
 from tests.e2e.core.windows._helpers import _decode
@@ -404,14 +405,17 @@ def _parse_marker(text: str) -> dict:
             "delegate": delegate, "delegate_ct": delegate_ct}
 
 
-def _identity_live(pid: int | None, ct: float | None) -> bool:
+def _identity_live(pid: int | None, ct: float | None, age: float) -> bool:
+    """update_lock's C1 verdict for one identity of a marker ``age`` seconds old."""
     if not pid or pid <= 0:
         return False
     try:
         proc = psutil.Process(pid)
         if not proc.is_running():
             return False
-        return ct is None or abs(proc.create_time() - ct) <= CT_TOLERANCE
+        if ct is None:  # v1 / no creation time: the pid may be reused, so only the age ceiling bounds it
+            return age <= UPDATE_MARKER_MAX_AGE_SECONDS
+        return abs(proc.create_time() - ct) <= CT_TOLERANCE
     except psutil.Error:
         return False
 
@@ -419,9 +423,10 @@ def _identity_live(pid: int | None, ct: float | None) -> bool:
 def _marker_live(text: str) -> str | None:
     """Who keeps the marker LIVE (``"owner <pid>"`` / ``"delegate <pid>"``), or None."""
     m = _parse_marker(text)
-    if _identity_live(m["pid"], m["ct"]):
+    age = time.time() - (m["started_at"] or 0.0)
+    if _identity_live(m["pid"], m["ct"], age):
         return f"owner {m['pid']}"
-    if _identity_live(m["delegate"], m["delegate_ct"]):
+    if _identity_live(m["delegate"], m["delegate_ct"], age):
         return f"delegate {m['delegate']}"
     return None