Bring the docs in line with the code

- python-backend/README: track analysis is implemented (2e0e6ad); the cache layout,
  the module table (lirc, screen, timers, podcasts, tippen) and the route table
  (track analysis, HA proxy, typing game) were missing pieces.
- docs/REPO_OVERVIEW: Mein Zimmer and the clock are implemented; Home Assistant is
  also reached over HTTP through the room page's proxy, not MQTT only; the IR remote,
  scripts/, the optional config sections and figure kind were not mentioned.
- web/README: the key table was the mockup's (Ctrl transport keys, TAB over 'all');
  ?pi=1 is now a preset with per-browser overrides, not a read-once flag; the room
  page and the typing game exist; eslint is part of the checks.
- Docstrings that described earlier designs: HaConfig (written as browser-direct in
  the same commit that built the proxy, a8ed350), services/__init__, events,
  playback, media, colors, tippen progress and AppHeader, lowPower.ts, and the
  'Hoerbuecher' spelling.

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

python-backend/musicmouse/services/__init__.py

@@ -1,7 +1,8 @@
 """Front-ends: things that mirror state outwards and turn requests into intents.
 
-``MqttService`` is the reference implementation. A web service would be another file
-here plus one line in the app - devices and reactions would not change.
+MQTT (Home Assistant), web (the browser), lirc (the IR remote) and the screen, timer and
+podcast services each live here; adding another is a file here plus a line in
+``__main__._build_services`` - devices and reactions do not change.
 """
 
 from musicmouse.services.base import Service