receiver: close paired devices before dropping the handle

Receiver.close() nulled its own handle first and only then closed its
paired devices. A paired device's feature_request() sends over the
receiver's handle, so the device.cleanups callbacks that run inside
Device.close() - release RGB SW control, restore onboard-profile mode -
were issued with handle=None, failed, and were silently swallowed. On
every clean Solaar quit a receiver-paired keyboard was left in host
mode; on the G915 TKL that means dead F-keys until a power cycle
(#3266). Wired devices were unaffected: Device.close() already runs
cleanups before clearing its handle, per its own comment.

Close the devices first, then drop the handle, mirroring Device.close().
Also log cleanup write failures in rgb_power.cleanup at debug level
instead of swallowing them silently, so a torn-down transport can't
hide; debug because failures are routine when the device is unplugged.

The regression test fails against the previous ordering.

lib/logitech_receiver/receiver.py

@@ -189,11 +189,12 @@ class Receiver:
     def close(self):
         if logger.isEnabledFor(logging.INFO):
             logger.info("%s: closing - handle %s %s", self, type(self.handle), self.handle)
-        handle, self.handle = self.handle, None
+        # Close paired devices first: their cleanup writes go over this receiver's handle.
         for _n, d in self._devices.items():
             if d:
                 d.close()
         self._devices.clear()
+        handle, self.handle = self.handle, None
         return handle and self.low_level.close(handle)
 
     def __del__(self):

lib/logitech_receiver/rgb_power.py

@@ -338,8 +338,8 @@ def cleanup(device):
             device.feature_request(SupportedFeature.PROFILE_MANAGEMENT, 0x60, b"\x03")
         elif device.features and SupportedFeature.ONBOARD_PROFILES in device.features:
             device.feature_request(SupportedFeature.ONBOARD_PROFILES, 0x10, b"\x01")
-    except Exception:
-        pass  # Device may already be offline
+    except Exception as e:
+        logger.debug("%s: cleanup release writes failed (device offline?): %s", device, e)
     if getattr(device, "_rgb_has_shutdown_cap", False):
         try:
             # SetRgbPowerMode(set=1, mode=0) — firmware off transition.

tests/logitech_receiver/test_receiver.py

@@ -369,3 +369,21 @@ def test_force_unpair_slot_no_handle():
 
     assert r.force_unpair_slot(2) is False
     r._unpair_device_per_receiver.assert_not_called()
+
+
+def test_close_keeps_handle_until_paired_devices_closed():
+    """Paired-device cleanup writes go over the receiver's handle, so
+    Receiver.close must close its devices before dropping it."""
+    device_info = DeviceInfo("11")
+    mock_low_level = LowLevelInterfaceFake(responses_unifying)
+    r = receiver.create_receiver(mock_low_level, device_info, lambda x: x)
+    handle_at_device_close = []
+    dev = mock.Mock()
+    dev.close.side_effect = lambda: handle_at_device_close.append(r.handle)
+    r._devices[1] = dev
+
+    r.close()
+
+    assert handle_at_device_close == [fake_hidpp.open_path("11")]
+    assert r.handle is None
+    assert r._devices == {}