Add IR remote control (LIRC) with a number-key content mapping

Adds a TCP client for lircd's classic protocol: play/pause/next/prev/
volume/mute map to the same intents every other front-end already
emits, and number keys 0-9 play an assigned album/audiobook from the
start or a podcast show's newest episode, resolved fresh on every
press. The mapping is configured in config.yml and editable from the
frontend: a small "Taste zuweisen" button on the play screen (or the
A+digit keyboard shortcut) opens a 10-key picker to assign whatever is
currently playing.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

python-backend/musicmouse/__main__.py

@@ -36,6 +36,7 @@ from musicmouse.library import MusicLibrary
 from musicmouse.library.analysis import build_analyzer
 from musicmouse.reactions import register_all
 from musicmouse.services.base import Service
+from musicmouse.services.lirc import LircService
 from musicmouse.services.mqtt import MqttService, build_entities
 from musicmouse.services.podcasts import PodcastFeedService
 from musicmouse.services.web import WebService
@@ -330,6 +331,12 @@ def _build_services(
     else:
         services.append(WebService(app, web_config, config_path))
 
+    lirc_config = app.config.general.lirc
+    if lirc_config is None:
+        _log.info("No lirc section in the config: the IR remote is off")
+    else:
+        services.append(LircService(app, lirc_config, clock=clock))
+
     # Unconditional: a show only starts downloading once someone drops a `feed.txt`
     # into its folder, so there is nothing to gate here with its own config section.
     web_service = next((s for s in services if isinstance(s, WebService)), None)