Fix broken map rendering, split GPS cleanup, receipt parser and design backlog

Leaflet's stylesheet was appended to document.head, so it never reached the
panel's shadow root: .leaflet-tile{position:absolute} never applied, tiles laid
out as in-flow images (~1040px inside a 190px box) and the marker pane ended up
far below the visible area. That is the real cause of the long-standing
"fragmented Leaflet rendering" finding and of the invisible vehicle pin - every
tile request had actually succeeded. The stylesheet now goes into the shadow
root and is awaited before the map is built.

Also in this round:
- Map tiles are always light (Google-Maps-style), no dark variant at night.
- Vehicle marker uses the real CI poi-car icons (poi-car-l >=34px, poi-car-s
  below), with a white halo so the outline stays readable on tiles.
- Removed the obsolete combined STANDORT_TRACKER field; only the split
  lat/lon sensors remain.
- Receipt upload: widened the try block so base64/save failures surface, and
  the frontend call site now reports a rejected service call.
- Generic receipt parser: total detection is line-based (letter-spaced
  headings, no more matching the SUMME-EUR column header, tax lines excluded),
  address heuristic handles 4-digit postcodes and single-line address blocks,
  and "Preis/L" matches without a spelled-out "Liter".
- Design backlog: red hairline frame on list rows (delete button bled through
  at fractional row heights) and select fields now use the grey background box.

Shell 10-receipt regression suite still passes; all changes verified live in
the audi_ha_test container.

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

homeassistant/pyscript/modules/einstellungen.py

@@ -77,16 +77,10 @@ OELWECHSEL_STRECKE_SENSOR = ""
 NAECHSTE_INSPEKTION_SENSOR = ""
 INSPEKTION_STRECKE_SENSOR = ""
 
-# Live-GPS-Position des Fahrzeugs (Übersicht -> Standort-Kachel). Erwartet
-# eine device_tracker.*-Entity mit "latitude"/"longitude"-Attributen (HA-
-# Konvention, siehe _standort() in frontend_veroeffentlichung.py) - jetzt
-# vom FMM003 geliefert.
-STANDORT_TRACKER = "device_tracker.testzone_fmm003"
-
-# Alternative zu STANDORT_TRACKER: manche Integrationen (z. B. flespi) liefern
-# Breiten-/Längengrad nicht als Attribute einer einzelnen device_tracker-
-# Entity, sondern als zwei eigene sensor-Entities. _standort() nutzt diese
-# beiden nur, wenn STANDORT_TRACKER leer ist oder keine Koordinaten liefert.
+# Live-GPS-Position des Fahrzeugs (Übersicht -> Standort-Kachel). Breiten-/
+# Längengrad als zwei eigene sensor-Entities (flespi liefert Koordinaten so,
+# nicht als Attribute einer device_tracker-Entity - siehe _standort() in
+# frontend_veroeffentlichung.py).
 STANDORT_LAT_SENSOR = ""
 STANDORT_LON_SENSOR = ""