Suppress signal handlers for the whole init (LXMF.LXMRouter too)

v1.0.2 only neutralised signal.signal around RNS.Reticulum(), but
LXMF.LXMRouter.__init__ also calls signal.signal(SIGINT/SIGTERM) (LXMRouter.py
308-309), so init still crashed with "signal only works in main thread of the
main interpreter" when the router was constructed in the executor thread.

Wrap the entire _start init (both constructors) with signal.signal neutralised
instead of just the RNS constructor. Confirmed via upstream source that the
only relevant signal registration sites are RNS/Reticulum.py:366-367 and
LXMF/LXMRouter.py:308-309, both module-attribute calls, so the module-level
patch intercepts both.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -214,11 +214,12 @@ action:
   apply on reload.
 - The identity is stored in `config/reticulum/identity` — back it up to keep the
   same address.
-- RNS is a standalone-daemon-style library. To embed it cleanly the integration
-  suppresses RNS's own signal handlers (so Home Assistant keeps ownership of
-  SIGINT/SIGTERM — important under Kubernetes) and unregisters its blocking
-  `atexit` persistence, persisting RNS/LXMF state itself, off the event loop,
-  on the `homeassistant_stop` event. RNS still spawns a couple of non-daemon
+- RNS and LXMF are standalone-daemon-style libraries — both install
+  SIGINT/SIGTERM handlers and `atexit` persistence in their constructors. To
+  embed them cleanly the integration suppresses those signal handlers during
+  init (so Home Assistant keeps ownership of SIGINT/SIGTERM — important under
+  Kubernetes) and unregisters their blocking `atexit` persistence, persisting
+  RNS/LXMF state itself, off the event loop, on the `homeassistant_stop` event. RNS still spawns a couple of non-daemon
   worker threads, so on shutdown you may see a "non-daemonic threads" notice and
   a short delay before the process exits (within the pod's termination grace
   period).

custom_components/reticulum/manifest.json

@@ -12,5 +12,5 @@
   "loggers": ["RNS", "LXMF"],
   "requirements": ["rns>=0.9.0", "lxmf>=0.6.0"],
   "single_config_entry": true,
-  "version": "1.0.2"
+  "version": "1.0.3"
 }

custom_components/reticulum/reticulum_client.py

@@ -51,6 +51,11 @@ _LOCAL_DESTINATION: Any = None
 _IDENTITY: Any = None
 _ANNOUNCE_HANDLER: Any = None
 
+
+def _noop_signal(*_args: Any, **_kwargs: Any) -> None:
+    """Drop-in for ``signal.signal`` used while initialising off the main thread."""
+    return None
+
 # How long (seconds) to wait for a path/identity to resolve before giving up on
 # an outbound message.
 PATH_RESOLVE_TIMEOUT = 15.0
@@ -148,7 +153,27 @@ class ReticulumManager:
         self._push_state()
 
     def _start(self) -> None:
-        """Blocking init. Runs in the executor thread."""
+        """Blocking init wrapper (executor thread).
+
+        Both ``RNS.Reticulum()`` and ``LXMF.LXMRouter()`` call
+        ``signal.signal()`` in their constructors, which only works on the main
+        thread. We run init in an executor thread, so neutralise ``signal.signal``
+        for the whole init. As a bonus this stops RNS/LXMF from hijacking Home
+        Assistant's own SIGINT/SIGTERM handling (needed for clean shutdown,
+        especially under Kubernetes).
+        """
+        patched = threading.current_thread() is not threading.main_thread()
+        saved_signal = signal.signal
+        if patched:
+            signal.signal = _noop_signal  # type: ignore[assignment]
+        try:
+            self._start_impl()
+        finally:
+            if patched:
+                signal.signal = saved_signal  # type: ignore[assignment]
+
+    def _start_impl(self) -> None:
+        """Blocking init. Runs in the executor thread (signals suppressed)."""
         global _RNS_INSTANCE, _LXM_ROUTER, _LOCAL_DESTINATION  # noqa: PLW0603
         global _IDENTITY, _ANNOUNCE_HANDLER  # noqa: PLW0603
         import LXMF  # noqa: PLC0415
@@ -247,18 +272,7 @@ class ReticulumManager:
             handle.write(contents)
 
     def _create_rns_instance(self, rns: Any) -> Any:
-        """Create the RNS instance from an executor thread.
-
-        ``Reticulum.__init__`` calls ``signal.signal()`` with no main-thread
-        guard, but signal handlers can only be installed from the main thread.
-        Since we (correctly) initialise off the event loop, we temporarily
-        neutralise ``signal.signal`` so init completes — and as a bonus this
-        stops RNS from hijacking Home Assistant's own SIGINT/SIGTERM handling,
-        which HA needs for clean shutdown (important under Kubernetes).
-        """
-        saved_signal = signal.signal
-        if threading.current_thread() is not threading.main_thread():
-            signal.signal = lambda *args, **kwargs: None  # type: ignore[assignment]
+        """Create the RNS instance (called with signal handlers suppressed)."""
         try:
             return rns.Reticulum(
                 configdir=self.storage_dir, loglevel=self.loglevel
@@ -274,8 +288,6 @@ class ReticulumManager:
                 raise
             _LOGGER.debug("Adopted existing Reticulum instance after %s", err)
             return adopted
-        finally:
-            signal.signal = saved_signal  # type: ignore[assignment]
 
     @staticmethod
     def _tame_exit_handler(obj: Any) -> None: