feat(train): Home opens on today's figures from the band (ADR 0030, D60)

While the Loop gave figures for today, Home shows them above the week:
steps, active time, last night's sleep and Nightly Recharge, as Profile
lists a day, tapped opening the day's page. Shown above Home's message
too, before a first workout; the week waits for one.

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_en.arb

@@ -732,5 +732,6 @@
   "bodyResting": "resting {bpm} bpm",
   "@bodyResting": {"placeholders": {"bpm": {"type": "int"}}},
   "bodyMax": "max {bpm} bpm",
-  "@bodyMax": {"placeholders": {"bpm": {"type": "int"}}}
+  "@bodyMax": {"placeholders": {"bpm": {"type": "int"}}},
+  "homeToday": "Today"
 }