feat(lite): mirror errors into the lite Console (copyable), not just toasts

Lite send/shield, unlock, and key-import failures were shown only as transient
toasts — impossible to copy. Route them through liteLog() so they also appear in
the lite Console (which has a Copy button), alongside the lifecycle/open/sync
errors the controller already logs:
- send/shield broadcast failures (App broadcast-result delivery)
- wallet unlock failure
- key import failure (controller; logs the error text only, never the key)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app.cpp

@@ -532,6 +532,10 @@ void App::update()
         // Deliver a completed async send/shield result to the waiting send_tab callback.
         wallet::LiteBroadcastResult broadcast;
         if (lite_wallet_->takeBroadcastResult(broadcast)) {
+            // Mirror failures into the lite Console (copyable) in addition to the toast the send UI
+            // shows — transient toasts are easy to miss and impossible to copy.
+            if (!broadcast.ok)
+                wallet::liteLog("Send/shield failed: " + broadcast.error);
             if (lite_send_callback_) {
                 lite_send_callback_(broadcast.ok, broadcast.ok ? broadcast.txid : broadcast.error);
                 lite_send_callback_ = nullptr;
@@ -2243,7 +2247,10 @@ void App::renderLiteUnlockPrompt()
             const bool ok = lite_wallet_->unlockWallet(pass);
             sodium_memzero(pass, sizeof(pass));
             if (ok) ui::Notifications::instance().success(TR("lite_unlock_ok"), 5.0f);
-            else    ui::Notifications::instance().error(TR("lite_unlock_failed"));
+            else {
+                wallet::liteLog(std::string("Unlock failed: ") + TR("lite_unlock_failed"));
+                ui::Notifications::instance().error(TR("lite_unlock_failed"));
+            }
             lite_unlock_prompt_ = false;
             ImGui::CloseCurrentPopup();
         }

src/wallet/lite_wallet_controller.cpp

@@ -896,6 +896,7 @@ LiteImportResult LiteWalletController::importKey(std::string spendingOrViewingKe
         LiteImportResult alt = runImport(transparentFirst ? "import" : "timport");
         if (alt.ok) out = alt;
     }
+    if (!out.ok) liteLog("Key import failed: " + out.error);  // error text only — never the key
     secureWipeLiteSecret(spendingOrViewingKey);  // wipe our copy after both attempts
     return out;
 }