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/app.h

@@ -163,6 +163,13 @@ public:
     bool supportsEmbeddedDaemon() const { return wallet::supportsEmbeddedDaemon(walletCapabilities()); }
     bool supportsFullNodeLifecycleActions() const { return wallet::supportsFullNodeLifecycleActions(walletCapabilities()); }
 
+    // Daemon (v1.3.0+) coinbase auto-shield status, from z_autoshieldstatus. "Not probed" / all-false on
+    // pre-1.3.0 daemons (no such RPC) — callers treat that as "the wallet handles auto-shield itself".
+    bool daemonAutoShieldProbed() const { return daemon_autoshield_probed_; }
+    bool daemonAutoShieldActive() const { return daemon_autoshield_active_; }
+    const std::string& daemonAutoShieldAddress() const { return daemon_autoshield_address_; }
+    const std::string& daemonAutoShieldDisabledReason() const { return daemon_autoshield_disabled_reason_; }
+
     // W7 QoL: a plaintext support-diagnostics snapshot (version, variant, daemon/RPC/wallet/log state)
     // for the "Copy diagnostics" action. Contains no secrets.
     std::string buildDiagnosticsReport();
@@ -958,6 +965,8 @@ private:
     // so a possibly-incomplete salvaged wallet isn't mistaken for fund loss. Warned once per session.
     bool wallet_auto_recovered_ = false;         // a salvage happened this session
     bool wallet_auto_recovered_warned_ = false;  // guard: only surface it once per session
+    bool wallet_degraded_ = false;               // v1.3.0+ opened the wallet in DEGRADED mode (no new HD keys)
+    bool wallet_degraded_warned_ = false;        // guard: surface the degraded-mode notice once per session
     bool show_wallet_recovered_dialog_ = false;  // auto-shown warning dialog
     // Complementary on-disk safety net for a salvage we DIDN'T witness this launch (happened on a prior
     // run, or under an external daemon whose startup output we never captured): if the active wallet loads
@@ -1248,6 +1257,9 @@ private:
     bool daemon_autoshield_probed_ = false;
     bool daemon_autoshield_active_ = false;
     std::atomic<bool> daemon_autoshield_probe_inflight_{false};
+    std::string daemon_autoshield_address_;          // z_autoshieldstatus fields (O1); empty on old daemons
+    std::string daemon_autoshield_disabled_reason_;  // daemon's reason auto-shield is off (e.g. seed not recoverable)
+    bool daemon_autoshield_seed_recoverable_ = false;
 
     // P4: Incremental transaction cache
     int last_tx_block_height_ = -1;  // block height at last full tx fetch
@@ -1440,6 +1452,7 @@ private:
     void renderWalletRecoveredDialog();   // warn that the node auto-recovered/salvaged wallet.dat
     void renderEmptyWalletWarningDialog();// warn that the active wallet is empty while a sibling holds funds
     void detectWalletAutoRecovery();      // scan daemon output for a salvage; fire the warning once/session
+    void detectWalletDegraded();          // scan daemon output for a DEGRADED-mode open; warn once/session
     void restoreOriginalWallet();         // swap the wallet.<ts>.bak back over the salvaged copy + restart
     void pumpWalletRestore();             // main-thread: surface the restore/rebuild op's result
     void rebuildWalletDatabase();         // rebuild a BDB-inconsistent wallet into a loadable one (helper)