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/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;
 }