feat(ui): surface daemon DEGRADED mode + v1.3.0 auto-shield status

Rec3 — v1.3.0+ opens a wallet that lost its hdchain in DEGRADED mode (existing funds spendable,
but no new HD-key derivation) instead of aborting. Add a daemon-log classifier
(walletOpenedDegraded) + detectWalletDegraded(), warned once per session. Pre-1.3.0 daemons
never emit that line, so it's a no-op there.

O1 — probe z_autoshieldstatus once per connection (now decoupled from our own toggle/balance) and,
in Settings, show whether the node handles auto-shield itself (+ its destination, or the daemon's
disabled_reason). The checkbox now governs only the wallet's fallback shielder, which defers to the
node. Nothing renders on pre-1.3.0 daemons (no such RPC), so behaviour is unchanged.

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

src/util/i18n.cpp

@@ -1250,6 +1250,8 @@ void I18n::loadBuiltinEnglish()
         strings_["wallet_recovered_restore"] = "Restore the original file instead";
         strings_["wallet_recovered_restore_sub"] = "Puts your largest untouched backup back in place, verbatim, then re-scans — slightly faster, but only as complete as that one file was. Your current file is kept as a dated backup either way.";
         strings_["wallet_recovered_notify"] = "Your wallet file needed a repair — your original was safely backed up. Open the app to review your options.";
+        strings_["wallet_degraded_notify"] = "Your wallet opened in reduced-function mode: existing funds are safe and spendable, but creating new addresses and shielding are disabled. Back up your seed phrase and restore it to fully repair the wallet.";
+        strings_["autoshield_by_node"] = "Auto-shield is handled by your node";
         // In-dialog recovery lifecycle (Offer → Working → Done/Failed) + disclosures.
         strings_["wallet_recovery_working_label"] = "Working";
         strings_["wallet_recovery_done"] = "Done";