IR remote: power key switches the screen; count irserver's repeats

KEY_POWER emits ToggleScreenRequested, which a new ScreenService turns into the
optional general.screen.toggle_command (musicdolphin: ansible's kiosk-screen). It is
a service, not a reaction, so the subprocess runs in its own task instead of holding
the bus; a press while one is still running is dropped, and failures, hangs and a
missing command are only logged.

irserver reports every line of a held button as repeat 00, so a slightly long press
on Next skipped several tracks and Power would switch the screen off and on again.
A line of the same button within 0.25s of the previous one now counts as a repeat.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

python-backend/tests/test_lirc.py

@@ -21,6 +21,7 @@ from musicmouse.events import (
     PlayRequested,
     PlaySeriesLatestRequested,
     PreviousTrackRequested,
+    ToggleScreenRequested,
     VolumeChangeRequested,
 )
 from musicmouse.services.lirc import LircService
@@ -265,6 +266,56 @@ async def test_volume_buttons_act_on_every_repeat(
     assert all(event.delta < 0 for event in seen)
 
 
+async def test_a_held_button_from_irserver_acts_once(
+    lircd: tuple[ScriptedLircd, asyncio.base_events.Server], sim: Simulation
+) -> None:
+    # irserver sends every line of a held button as repeat 00.
+    station, server = lircd
+    port = server.sockets[0].getsockname()[1]
+    seen: list[Event] = []
+    sim.bus.subscribe(NextTrackRequested, seen.append)
+    sim.bus.subscribe(VolumeChangeRequested, seen.append)
+    assert isinstance(sim.clock, FakeClock)
+
+    task = await _run_service(sim, _lirc_config(port))
+    try:
+        await station.wait_connected()
+        for _ in range(3):
+            await station.send("b7b0000000000000 00 key_forward hauppauge")
+            await sim.clock.advance(0.11)
+        await sim.clock.advance(1.0)
+        await station.send("b7b0000000000000 00 key_forward hauppauge")
+        # Volume still ramps for as long as it is held.
+        for _ in range(3):
+            await station.send("b720000000000000 00 key_volumeup hauppauge")
+            await sim.clock.advance(0.11)
+        await sim.bus.drain()
+    finally:
+        task.cancel()
+
+    assert [type(event) for event in seen] == [NextTrackRequested] * 2 + [VolumeChangeRequested] * 3
+
+
+async def test_the_power_button_toggles_the_screen(
+    lircd: tuple[ScriptedLircd, asyncio.base_events.Server], sim: Simulation
+) -> None:
+    station, server = lircd
+    port = server.sockets[0].getsockname()[1]
+    seen: list[Event] = []
+    sim.bus.subscribe(ToggleScreenRequested, seen.append)
+
+    task = await _run_service(sim, _lirc_config(port))
+    try:
+        await station.wait_connected()
+        await station.send("b7d0000000000000 00 key_power hauppauge")
+        await station.send("b7d0000000000000 00 key_power hauppauge")  # still held
+        await sim.bus.drain()
+    finally:
+        task.cancel()
+
+    assert len(seen) == 1
+
+
 async def test_mute_toggles_and_restores(
     lircd: tuple[ScriptedLircd, asyncio.base_events.Server], sim: Simulation
 ) -> None:
@@ -281,6 +332,9 @@ async def test_mute_toggles_and_restores(
         await sim.bus.drain()
         assert sim.player.volume == 0
 
+        # A second press, not the first one held - see the repeat counting below.
+        assert isinstance(sim.clock, FakeClock)
+        await sim.clock.advance(1.0)
         await station.send("0 00 KEY_MUTE Hauppauge")
         await sim.bus.drain()
         assert sim.player.volume == 37