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
-    static int s_expanded_row = -1;
+    // Open inline detail, keyed by row identity (history::rowKey), NOT by list index: the display list is rebuilt
+    // 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
-        int filterHash = type_filter * 1000003 + s_sort_mode * 7919 + filtered_count * 31 + static_cast<int>(search_str.size());
-        if (filterHash != s_prev_filter_hash) {
+        // Reset page (and collapse the open row) only when a filter INPUT changes (type, sort, or the search text).
+        // The row count is data: a new/removed row just clamps the page below instead of bouncing to page 1.
+        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