fix: preserve legacy plugin catalogs and protect helper token initialization

artemis/runtime/helper_manager.py

@@ -77,6 +77,8 @@ from typing import Any
 import urllib.error
 import urllib.request
 
+from filelock import FileLock
+
 from artemis.config.constants import ENV_ARTEMIS_HELPER_AUTO_INSTALL
 from artemis.config.paths import get_temp_dir
 from artemis.runtime.adb_endpoint import adb_command
@@ -323,7 +325,7 @@ class AccessibilityHelperManager:
             if re.fullmatch(r"[0-9a-f]{32,128}", text):
                 self._token = text
                 return text
-        except OSError:
+        except FileNotFoundError:
             pass
         token = secrets.token_hex(24)
         try:
@@ -550,6 +552,15 @@ class AccessibilityHelperManager:
         root.mkdir(parents=True, exist_ok=True)
         digest = hashlib.sha256(serial.encode("utf-8")).hexdigest()[:16]
         path = root / f"{digest}.mutex"
+        # An age-based lease alone can be stolen from a live, delayed owner.
+        # Retain the legacy lease for coexistence with older Artemis processes,
+        # but serialize current processes with a kernel lock released on exit.
+        with FileLock(path.with_suffix(".guard"), timeout=_PROVISION_MUTEX_TIMEOUT_SECONDS):
+            with self._legacy_provision_mutex(path, serial):
+                yield
+
+    @contextmanager
+    def _legacy_provision_mutex(self, path: Path, serial: str):
         started = time.monotonic()
         while True:
             try: