fix(tui): use direct parent identity in slash worker

Remove process creation time and pid_exists from the slash worker parent-death predicate. The worker remains attached while its original PPID matches and keeps the existing in-flight grace behavior.\n\nRefs #62505

tests/test_slash_worker_watchdog.py

@@ -1,21 +1,24 @@
-import psutil
+import inspect
 
 from tui_gateway import slash_worker
 
 
 def test_is_orphaned_true_when_ppid_changes():
     # Our parent went away and we were reparented to a subreaper/init.
-    assert slash_worker._is_orphaned(1234, 1.0, getppid=lambda: 999999) is True
+    assert slash_worker._is_orphaned(1234, getppid=lambda: 999999) is True
 
 
-def test_is_orphaned_true_when_parent_create_time_mismatch():
-    # Same ppid but a different create_time means the PID was reused.
-    me = psutil.Process()
-    assert slash_worker._is_orphaned(me.pid, 0.0, getppid=lambda: me.pid) is True
+def test_is_orphaned_false_when_direct_parent_is_unchanged():
+    original_ppid = 1234
+    assert slash_worker._is_orphaned(original_ppid, getppid=lambda: original_ppid) is False
 
 
-def test_is_orphaned_false_when_parent_alive_and_matches():
-    me = psutil.Process()
-    assert (
-        slash_worker._is_orphaned(me.pid, me.create_time(), getppid=lambda: me.pid) is False
-    )
+def test_parent_death_watchdog_contract_has_no_create_time_plumbing():
+    assert list(inspect.signature(slash_worker._is_orphaned).parameters) == [
+        "original_ppid",
+        "getppid",
+    ]
+    assert list(inspect.signature(slash_worker._start_parent_death_watchdog).parameters) == [
+        "original_ppid",
+    ]
+    assert "psutil" not in slash_worker.__dict__

tui_gateway/slash_worker.py

@@ -25,8 +25,6 @@ import sys
 import threading
 import time
 
-import psutil
-
 import cli as cli_mod
 from cli import HermesCLI
 from rich.console import Console
@@ -51,18 +49,9 @@ _ORPHAN_GRACE_S = max(0.0, _env_float("HERMES_SLASH_WATCHDOG_GRACE_S", 5.0))
 _in_flight = threading.Event()  # set while a command is executing
 
 
-def _is_orphaned(original_ppid, parent_create_time, getppid=os.getppid) -> bool:
-    """True once our spawning gateway is gone. Compare to the ORIGINAL ppid
-    (never ==1: Linux reparents to a subreaper) and guard PID reuse via
-    create_time."""
-    if getppid() != original_ppid:
-        return True
-    try:
-        if not psutil.pid_exists(original_ppid):
-            return True
-        return psutil.Process(original_ppid).create_time() != parent_create_time
-    except psutil.Error:
-        return True
+def _is_orphaned(original_ppid, getppid=os.getppid) -> bool:
+    """Return whether this worker no longer has its original POSIX parent."""
+    return getppid() != original_ppid
 
 
 def _prepare_slash_worker_runtime() -> None:
@@ -86,9 +75,9 @@ def _prepare_slash_worker_runtime() -> None:
     wait_for_mcp_discovery()
 
 
-def _start_parent_death_watchdog(original_ppid, parent_create_time) -> None:
+def _start_parent_death_watchdog(original_ppid) -> None:
     def _loop():
-        while not _is_orphaned(original_ppid, parent_create_time):
+        while not _is_orphaned(original_ppid):
             time.sleep(_WATCHDOG_POLL_S)
         deadline = time.monotonic() + _ORPHAN_GRACE_S
         while _in_flight.is_set() and time.monotonic() < deadline:
@@ -145,11 +134,7 @@ def main():
     # Start before the (hundreds-of-ms) HermesCLI build — that window is itself
     # an orphan risk if the gateway dies mid-spawn.
     orig_ppid = os.getppid()
-    try:
-        parent_create_time = psutil.Process(orig_ppid).create_time()
-    except psutil.Error:
-        parent_create_time = 0.0
-    _start_parent_death_watchdog(orig_ppid, parent_create_time)
+    _start_parent_death_watchdog(orig_ppid)
     _prepare_slash_worker_runtime()
 
     with contextlib.redirect_stdout(io.StringIO()), contextlib.redirect_stderr(io.StringIO()):