fix(core): refresh transaction history on the Mining tab

The Mining tab shows earnings derived from transaction history, but it
was not treated as a wallet-data page, so newly mined or paid-out
earnings did not appear until the user left the tab and came back. A
coinbase row also changes category in place (immature becomes generate
at maturity, or orphan on a reorg), and the Recent merge kept both the
old and the new row, double-counting the earnings.

- The Mining tab now gets the cheap between-blocks Recent poll: one
  listtransactions per new block, bounded by the 15 s transaction-age
  timer, once history has loaded. It never runs a full routine scan and
  never pre-empts an owed dirty cycle; tracked sends still take their
  normal cycle on any page.
- The shielded-payout probe runs only while the pool miner is running,
  since pool payouts are shielded receives while a solo miner's earnings
  are transparent coinbase rows.
- The Recent merge drops the previous row of the other coinbase category
  when a coinbase transitions, so maturing or reorged rewards are no
  longer counted twice. A non-coinbase row sharing the txid is left
  alone.

Behaviour change: mining earnings update on the Mining tab per block
instead of only on tab re-entry, and maturing or reorged coinbase rows
no longer double-count.

Tests: the per-block poll gate (one poll per block, due only after
history loads, held while dirty or addresses are dirty), the Mining-page
cycle shaping, and the coinbase transition merge for immature to
generate, generate to orphan, and a shared-txid non-coinbase row.

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

src/app_network.cpp

@@ -886,6 +886,7 @@ void App::onDisconnected(const std::string& reason)
     confirmed_tx_ids_.clear();
     confirmed_cache_block_ = -1;
     last_tx_block_height_ = -1;
+    mining_tx_poll_block_ = -1;
     pending_opids_.clear();
     pending_send_info_.clear();
     // Resolve any deferred send callbacks so their UI doesn't spin forever on disconnect.
@@ -1207,6 +1208,7 @@ bool App::currentPageNeedsWalletDataRefresh() const
 bool App::shouldRunWalletTransactionRefresh() const
 {
     if (currentPageNeedsWalletDataRefresh()) return true;
+    if (current_page_ == ui::NavPage::Mining) return true;   // C119: refreshTransactionData() narrows it to the Recent poll
     if (!send_txids_.empty()) return true;
     return transactions_dirty_;
 }
@@ -2637,13 +2639,32 @@ bool App::refreshTransactionData()
     in.routineScanWork = work.routineWork;
     in.syncing = effectivelySyncing();
     in.heightKnown = tip > 0;
-    in.recentDue = currentPageNeedsWalletDataRefresh() && shouldRefreshRecentTransactions();
+    const bool walletPage = currentPageNeedsWalletDataRefresh();
+    // C119: the Mining tab shows history-derived earnings but only gets the cheap per-block Recent poll.
+    const bool miningPoll = current_page_ == ui::NavPage::Mining && !walletPage;
+    in.recentDue = walletPage && shouldRefreshRecentTransactions();
+    if (miningPoll) {
+        using Refresh = services::NetworkRefreshService;
+        in = services::shapeTxCycleForMiningPage(in);
+        services::MiningTxPollInputs mp;
+        mp.tip = tip;
+        mp.lastPolledTip = mining_tx_poll_block_;
+        mp.txAgeDue = network_refresh_.isDue(Refresh::Timer::TxAge);
+        mp.historyLoaded = last_tx_block_height_ >= 0;
+        mp.dirty = transactions_dirty_;
+        mp.addressesDirty = addresses_dirty_;
+        in.recentDue = services::miningTxPollDue(mp);
+    }
     // What this cycle is without and with a routine wallet-wide scan: the scan budget (the governor)
     // decides between the two.
     in.gateOpen = false;
     const TxCycle held = services::decideTxCycle(in);
     in.gateOpen = true;
-    const TxCycle open = services::decideTxCycle(in);
+    TxCycle open = services::decideTxCycle(in);
+    // Pool payouts are shielded receives (a z_listreceivedbyaddress probe finds them); a solo miner's earnings
+    // are transparent coinbase rows, so on the Mining tab the probe runs only while the pool miner is.
+    if (miningPoll && open == TxCycle::RecentWithProbe && !(xmrig_manager_ && xmrig_manager_->isRunning()))
+        open = TxCycle::Recent;
 
     const double now = scanClockNow();
     const auto sig = currentScanSignals();
@@ -2669,9 +2690,13 @@ bool App::refreshTransactionData()
         return heldBack;
     case TxCycle::Recent:
         startRecentTransactionPoll(false, {});
+        if (miningPoll && network_refresh_.jobInProgress(services::NetworkRefreshService::Job::Transactions))
+            mining_tx_poll_block_ = tip;   // dispatched (the job guard was clear on entry): one poll per block
         return heldBack;
     case TxCycle::RecentWithProbe:
         startRecentTransactionPoll(true, ticket);
+        if (miningPoll && network_refresh_.jobInProgress(services::NetworkRefreshService::Job::Transactions))
+            mining_tx_poll_block_ = tip;
         return false;
     case TxCycle::Full:
     case TxCycle::Light: