fix(history): keep wallet-created sends visible

Replay cached outgoing viewtransaction entries during transaction refresh so shielded sends created from the wallet remain in the History tab after send tracking is cleared.

Keep incomplete tracked sends retryable, preserve cached send timestamp/confirmation metadata, and emit a send placeholder from gettransaction metadata when viewtransaction enrichment is not yet available.

Add regression coverage for cached sends, retryable empty entries, placeholder sends, and send txid cleanup behavior.

src/services/network_refresh_service.h

@@ -148,6 +148,8 @@ public:
 
     struct TransactionViewCacheEntry {
         std::string from_address;
+        std::int64_t timestamp = 0;
+        int confirmations = 0;
         struct Output {
             std::string address;
             double value = 0.0;