feat(train): a ride's distance from the wheel where GPS falls short (ADR 0030, D49)

The speed sensor's wheel gives a ride's distance, splits, progress and live
speed where GPS made less than 90 % of its way (a turbo trainer, a tunnel);
its circumference starts at 2105 mm, is learnt from rides with 2 km of GPS
or typed on the Record sheet.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/train/halkyon_train_flutter/lib/l10n/app_de.arb

@@ -540,5 +540,11 @@
   "workoutPedalling": "Trittfrequenz",
   "workoutAverageCadence": "durchschnittliche Trittfrequenz",
   "workoutNormalisedPower": "normalisierte Leistung",
-  "workoutRpmValue": "{rpm} U/min"
+  "workoutRpmValue": "{rpm} U/min",
+  "recordWheel": "Radumfang",
+  "recordWheelMeasured": "{mm} mm, per GPS gemessen",
+  "recordWheelTyped": "{mm} mm, wie du ihn eingegeben hast",
+  "recordWheelDefault": "{mm} mm, bis GPS ihn auf 2 km Fahrt gemessen hat",
+  "recordWheelHint": "In Millimetern, wie auf dem Reifen (700×25C: 2105); leer, damit GPS ihn misst",
+  "recordWheelSave": "Speichern"
 }