fix(history): keep the open detail row across paging and filtering

The inline detail panel was tracked by the filtered list index. The
display list is rebuilt and re-sorted on every data change, sort switch
or filter edit, so a stored index pointed at a different transaction
after the rebuild, and a page reset was triggered by any change in the
row count, bouncing the view back to page 1.

- The open row is now tracked by a stable content key (txid, display
  type, address and the amount's exact bits) so the right row stays open
  across rebuilds.
- The page resets and the open row collapses only when a filter input
  changes (type, sort or the full search text). A new or removed row is
  data and now just clamps the current page.
- The open row is also cleared on page navigation and when the list
  empties, so a wallet switch does not resurrect an old expansion.

Adds pure helpers rowKey/filterInputsChanged to
transactions_tab_helpers.h.

Tests: rowKey distinguishes each field and separates +0.0 from -0.0, and
filterInputsChanged latches each input change but not the first frame.

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

src/ui/windows/transactions_tab.cpp

@@ -177,12 +177,13 @@ void RenderTransactionsTab(App* app)
     std::string txLoadingText = app->transactionRefreshProgressText();
     bool txLoading = !txLoadingText.empty();
 
-    // Expanded row index for inline detail
+    // Open inline detail, keyed by row identity (history::rowKey), NOT by list index: the display list is rebuilt
-    static int s_expanded_row = -1;
+    // and re-sorted on every change, so an index would land on a different transaction. Empty = none open.
+    static std::string s_expanded_key;
 
     // Pagination state
     static int s_current_page = 0;
-    static int s_prev_filter_hash = 0;  // detect filter changes to reset page
+    static history::FilterInputs s_prev_filter;  // detect filter-input changes to reset page
 
     // ================================================================
     // Summary Cards — Received | Sent | Mined
@@ -550,12 +551,13 @@ void RenderTransactionsTab(App* app)
         int perPage = std::max(10, (int)schema::UI().drawElement("tabs.transactions", "rows-per-page").sizeOr(50.0f));
         int totalPages = std::max(1, (filtered_count + perPage - 1) / perPage);
 
-        // Reset page when filters change
+        // Reset page (and collapse the open row) only when a filter INPUT changes (type, sort, or the search text).
-        int filterHash = type_filter * 1000003 + s_sort_mode * 7919 + filtered_count * 31 + static_cast<int>(search_str.size());
+        // The row count is data: a new/removed row just clamps the page below instead of bouncing to page 1.
-        if (filterHash != s_prev_filter_hash) {
+        if (history::filterInputsChanged(s_prev_filter, type_filter, s_sort_mode, search_str)) {
             s_current_page = 0;
-            s_prev_filter_hash = filterHash;
+            s_expanded_key.clear();
         }
+        if (filtered_count == 0) s_expanded_key.clear();   // wallet switch / emptied list: don't resurrect an old expansion
         if (s_current_page >= totalPages) s_current_page = totalPages - 1;
         if (s_current_page < 0) s_current_page = 0;
 
@@ -582,7 +584,7 @@ void RenderTransactionsTab(App* app)
                 ImGui::BeginDisabled(s_current_page == 0);
                 if (TactileButton(ICON_MD_FIRST_PAGE "##txFirst", ImVec2(btnW, btnW), Type().iconSmall())) {
                     s_current_page = 0;
-                    s_expanded_row = -1;
+                    s_expanded_key.clear();
                 }
                 ImGui::EndDisabled();
 
@@ -592,7 +594,7 @@ void RenderTransactionsTab(App* app)
                 ImGui::BeginDisabled(s_current_page == 0);
                 if (TactileButton(ICON_MD_CHEVRON_LEFT "##txPrev", ImVec2(btnW, btnW), Type().iconSmall())) {
                     s_current_page--;
-                    s_expanded_row = -1;
+                    s_expanded_key.clear();
                 }
                 ImGui::EndDisabled();
 
@@ -619,7 +621,7 @@ void RenderTransactionsTab(App* app)
                 ImGui::BeginDisabled(s_current_page >= totalPages - 1);
                 if (TactileButton(ICON_MD_CHEVRON_RIGHT "##txNext", ImVec2(btnW, btnW), Type().iconSmall())) {
                     s_current_page++;
-                    s_expanded_row = -1;
+                    s_expanded_key.clear();
                 }
                 ImGui::EndDisabled();
 
@@ -629,7 +631,7 @@ void RenderTransactionsTab(App* app)
                 ImGui::BeginDisabled(s_current_page >= totalPages - 1);
                 if (TactileButton(ICON_MD_LAST_PAGE "##txLast", ImVec2(btnW, btnW), Type().iconSmall())) {
                     s_current_page = totalPages - 1;
-                    s_expanded_row = -1;
+                    s_expanded_key.clear();
                 }
                 ImGui::EndDisabled();
             }
@@ -686,7 +688,8 @@ void RenderTransactionsTab(App* app)
                 for (int fi = pageStart; fi < pageEnd; fi++) {
                     size_t i = filtered_indices[fi];
                     const auto& tx = display_txns[i];
-                    bool is_expanded = (s_expanded_row == static_cast<int>(i));
+                    const std::string rk = history::rowKey(tx.txid, tx.display_type, tx.address, tx.amount);   // <= perPage rows/frame
+                    bool is_expanded = !s_expanded_key.empty() && s_expanded_key == rk;
 
                     ImGui::PushID(static_cast<int>(i));
                     ImVec2 rowPos = ImGui::GetCursorScreenPos();
@@ -832,7 +835,7 @@ void RenderTransactionsTab(App* app)
                     // Click to expand/collapse + invisible button for interaction
                     ImGui::InvisibleButton("##txRow", ImVec2(innerW, rowH));
                     if (ImGui::IsItemClicked(0)) {
-                        s_expanded_row = is_expanded ? -1 : static_cast<int>(i);
+                        if (is_expanded) s_expanded_key.clear(); else s_expanded_key = rk;
                     }
 
                     // Tooltip

src/ui/windows/transactions_tab_helpers.h

@@ -5,6 +5,8 @@
 // Pure helpers behind the History tab (no ImGui), so they can be unit-tested.
 #include "../../data/wallet_state.h"
 #include <cstddef>
+#include <cstdio>
+#include <cstring>
 #include <cstdint>
 #include <string>
 #include <string_view>
@@ -45,6 +47,45 @@ inline TxidGroups groupByTxid(const std::vector<TransactionInfo>& txs)
     return g;
 }
 
+// Stable identity of a display row, used to keep an inline detail panel open across list rebuilds.
+// txid alone is not unique (a tx can show several rows: multiple receive outputs, unmerged legs), so
+// add the display type, address and the amount's exact bits. Two rows identical in all four are the same
+// logical payment and expanding both is acceptable.
+inline std::string rowKey(const std::string& txid, const std::string& displayType,
+                          const std::string& address, double amount)
+{
+    std::uint64_t bits = 0;
+    std::memcpy(&bits, &amount, sizeof bits);
+    char hex[17];
+    std::snprintf(hex, sizeof hex, "%016llx", static_cast<unsigned long long>(bits));
+    std::string k;
+    k.reserve(txid.size() + displayType.size() + address.size() + 20);
+    k.append(txid).push_back('|');
+    k.append(displayType).push_back('|');
+    k.append(address).push_back('|');
+    k.append(hex);
+    return k;
+}
+
+// The inputs that decide which rows the History list shows and in what order.
+struct FilterInputs {
+    int type = 0;
+    int sort = 0;
+    std::string search;
+};
+
+// True (and `prev` updated) when type, sort or the FULL search text changed since last call. The caller
+// then resets to page 1 and collapses the open row. Starts at the defaults (0, 0, "") so the first frame
+// does not count as a change.
+inline bool filterInputsChanged(FilterInputs& prev, int type, int sort, const std::string& search)
+{
+    if (prev.type == type && prev.sort == sort && prev.search == search) return false;
+    prev.type = type;
+    prev.sort = sort;
+    prev.search = search;
+    return true;
+}
+
 } // namespace history
 } // namespace ui
 } // namespace dragonx

tests/test_phase4.cpp

@@ -10570,6 +10570,31 @@ void testHistoryTxidGroups()
     }
 }
 
+
+// History row identity + filter-change detection (c196): a kept-open detail panel must survive list
+// rebuilds (keyed by content, not index) and page/filter changes must reset and collapse.
+void testHistoryFilterInputs()
+{
+    using namespace dragonx::ui::history;
+    // rowKey distinguishes each field, and amount by exact bits (so +0.0 != -0.0).
+    EXPECT_TRUE(rowKey("tx","Sent","zaddr",1.0) == rowKey("tx","Sent","zaddr",1.0));
+    EXPECT_TRUE(rowKey("tx","Sent","zaddr",1.0) != rowKey("tx2","Sent","zaddr",1.0));
+    EXPECT_TRUE(rowKey("tx","Sent","zaddr",1.0) != rowKey("tx","Recv","zaddr",1.0));
+    EXPECT_TRUE(rowKey("tx","Sent","zaddr",1.0) != rowKey("tx","Sent","taddr",1.0));
+    EXPECT_TRUE(rowKey("tx","Sent","zaddr",1.0) != rowKey("tx","Sent","zaddr",2.0));
+    EXPECT_TRUE(rowKey("tx","Sent","zaddr",0.0) != rowKey("tx","Sent","zaddr",-0.0));
+
+    // filterInputsChanged: first call at defaults is not a change; each input change is, and latches.
+    FilterInputs prev;
+    EXPECT_TRUE(!filterInputsChanged(prev, 0, 0, ""));          // defaults -> no change
+    EXPECT_TRUE(filterInputsChanged(prev, 1, 0, ""));           // type changed
+    EXPECT_TRUE(!filterInputsChanged(prev, 1, 0, ""));          // same -> latched
+    EXPECT_TRUE(filterInputsChanged(prev, 1, 2, ""));           // sort changed
+    EXPECT_TRUE(filterInputsChanged(prev, 1, 2, "abc"));        // search changed
+    EXPECT_TRUE(!filterInputsChanged(prev, 1, 2, "abc"));       // same -> latched
+    EXPECT_TRUE(filterInputsChanged(prev, 1, 2, "ab"));         // full-text change (prefix differs)
+}
+
 // tx_revision starts at >=1 (a UI cache's 0 sentinel never matches), each helper adds exactly 1, the helpers
 // never touch last_tx_update, and clear() bumps without resetting, so no earlier revision ever recurs.
 void testWalletStateTxRevision()
@@ -18060,6 +18085,7 @@ int main()
     testLiteTransactionsAreNewestFirst();
     testSameTransactionList();
     testHistoryTxidGroups();
+    testHistoryFilterInputs();
     testWalletStateTxRevision();
     testTransactionRefreshRevision();
     testLiteSendShowsRecipientFromOutgoing();