feat(wallet): persist history and surface pending sends

Add an encrypted SQLite transaction history cache with cached tip metadata and
per-address shielded scan progress so startup and full refreshes avoid
re-scanning every z-address while still invalidating on wallet/address/rescan
changes.

Improve wallet history loading by paging transparent transactions, preserving
cached shielded and sent rows, keeping recent/unconfirmed activity visible, and
classifying mining-address receives. Show z_sendmany opid sends immediately in
History and Overview, pin pending rows through refreshes, and apply optimistic
address/balance debits until opids resolve.

Add timestamped RPC console tracing by source/method without logging params or
results, reduce redundant refresh/RPC calls, and cache Explorer recent block
summaries in SQLite.

Expand focused tests for transaction cache encryption, scan-progress
persistence/invalidation, history preservation, operation-status parsing,
pending send visibility, and Explorer/RPC refresh behavior.

src/ui/pages/settings_page.cpp

@@ -1484,6 +1484,7 @@ void RenderSettingsPage(App* app) {
                         if (app->rpc() && app->rpc()->isConnected() && app->worker()) {
                             app->worker()->post([rpc = app->rpc()]() -> rpc::RPCWorker::MainCb {
                                 try {
+                                    rpc::RPCClient::TraceScope trace("Settings / Test connection");
                                     rpc->call("getinfo");
                                     return []() {
                                         Notifications::instance().success("RPC connection OK");