feat(telemetry): add ter_result and applied attributes to tx.process span

Enriches the tx.process span with final outcome after batch application:
- ter_result: the TER code string (e.g., "tesSUCCESS", "tecPATH_DRY")
- applied: boolean whether the transaction was included in the ledger

These attributes complete the tx.process span lifecycle — it now captures
identity (tx_type, tx_hash), intent (fee, sequence), and outcome
(ter_result, applied) for full workflow traceability.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/xrpld/app/misc/NetworkOPs.cpp

@@ -1563,6 +1563,11 @@ NetworkOPsImp::apply(std::unique_lock<std::mutex>& batchLock)
         auto newOL = registry_.get().getOpenLedger().current();
         for (TransactionStatus const& e : transactions)
         {
+            if (e.span && *e.span)
+            {
+                e.span->setAttribute(tx_span::attr::terResult, transToken(e.result).c_str());
+                e.span->setAttribute(tx_span::attr::applied, e.applied);
+            }
             e.transaction->clearSubmitResult();
 
             if (e.applied)