feat(wallet): richer detail in the wallet-switch progress modal

The switch modal now shows more than a bare phase line:
- The title carries the target wallet ("Switching wallet — savings") and a
  "from <previous>" caption for context (names prettified: wallet.dat → "Default
  wallet", wallet-<name>.dat → "<name>", in-place links → "External wallet").
- During the Reconnecting phase — the ~30-60s where the node loads the block
  index, verifies, and rescans — it surfaces the node's LIVE init stage
  (state_.warmup_status/description via the existing translateWarmup mapping:
  "Loading blockchain data…", "Verifying blockchain…", "Scanning for
  transactions…") instead of a static "Reconnecting…".
- An elapsed timer (m:ss) so the wait visibly progresses.

i18n: from/elapsed/default-wallet/external-wallet labels (EN + 8 languages,
additive; no new CJK glyphs). No switch-flow logic change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

res/lang/fr.json

@@ -1295,7 +1295,11 @@
     "sweep_toggle": "Balayer vers mon portefeuille (ne pas conserver la clé)",
     "sweep_tx": "Transaction :",
     "switch_progress_background": "Continuer en arrière-plan",
+    "switch_progress_default_wallet": "Portefeuille par défaut",
+    "switch_progress_elapsed": "Écoulé",
+    "switch_progress_external_wallet": "Portefeuille externe",
     "switch_progress_failed_title": "Échec du changement de portefeuille",
+    "switch_progress_from_label": "depuis",
     "switch_progress_hint": "Un arrêt propre peut prendre jusqu'à une minute.",
     "switch_progress_reconnecting": "Reconnexion",
     "switch_progress_starting": "Démarrage du nœud sur le nouveau portefeuille",