revert(settings): drop the page-level card masonry

Page-level two-column masonry made the cards narrow and fought their internal
layouts. Revert the whole-page band (full-width stacked cards again) and keep
the internal NODE & SECURITY two-column — the better lever is breaking up the
large cards internally, not columning the page. The Explorer row-start-X fix is
kept (correct at full width too).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ui/pages/settings_page.cpp

@@ -643,25 +643,6 @@ void RenderSettingsPage(App* app) {
     ImFont* body2   = Type().body2();
     ImFont* sub1    = Type().subtitle1();
 
-    // ====================================================================
-    // Masonry: a full-width Theme & Language card, then a two-column band
-    // (Wallet / Node & Security on the left; Explorer / Chat & Contacts on the
-    // right) when the page is wide enough, then full-width About + Debug below.
-    // Within the band we shadow `availWidth` to the column width (every card
-    // reads it) and float the right column with Indent() — a one-shot cursor set
-    // can't hold a column across line-advances. Each card's own responsive gates
-    // collapse their internal columns at this narrower width.
-    // ====================================================================
-    const float msFullWidth = availWidth;
-    const float msColGap = Layout::spacingXl();
-    // Threshold is in logical px (× dpiScale): two columns once each is usable
-    // (~390 logical wide). Kept low enough to engage under OS display scaling,
-    // where the panel's real-px width is smaller in logical terms.
-    const bool  msTwoCol = availWidth > 780.0f * Layout::dpiScale();
-    const float msColW = msTwoCol ? (msFullWidth - msColGap) * 0.5f : msFullWidth;
-    ImVec2 msColTop(0.0f, 0.0f);   // captured when the two-column band begins (below Theme)
-    float  msLeftBottomY = 0.0f;
-
     // ====================================================================
     // THEME & LANGUAGE — card (draw-first approach; avoids ChannelsSplit
     //   which breaks BeginCombo popup rendering in some ImGui versions)
@@ -1318,12 +1299,6 @@ void RenderSettingsPage(App* app) {
 
     ImGui::Dummy(ImVec2(0, gap));
 
-    // Begin the two-column band: Wallet / Node & Security fill the left column.
-    if (msTwoCol) {
-        msColTop = ImGui::GetCursorPos();
-        availWidth = msColW;
-    }
-
     // ====================================================================
     // WALLET — card (privacy/daemon toggles + collapsible tools)
     // ====================================================================
@@ -2375,17 +2350,7 @@ void RenderSettingsPage(App* app) {
         }
     }
 
-    // End of the left column (Wallet / Node & Security). In two-column mode jump
+    ImGui::Dummy(ImVec2(0, gap));
-    // back to the band's top and indent so Explorer / Chat fill the right column;
-    // otherwise just add the usual inter-card gap.
-    if (msTwoCol) {
-        msLeftBottomY = ImGui::GetCursorPosY();
-        ImGui::SetCursorPosY(msColTop.y);
-        ImGui::Indent(msColW + msColGap);
-        ImGui::SetCursorPosX(msColTop.x + msColW + msColGap);
-    } else {
-        ImGui::Dummy(ImVec2(0, gap));
-    }
 
     // ====================================================================
     // EXPLORER & OPTIONS — full-width card
@@ -2462,15 +2427,6 @@ void RenderSettingsPage(App* app) {
         ImGui::PopFont();
     }
 
-    // End of the two-column band. Un-indent, drop below the taller column, and
-    // restore full width so About + Debug span the page.
-    if (msTwoCol) {
-        ImGui::Unindent(msColW + msColGap);
-        const float msRightBottomY = ImGui::GetCursorPosY();
-        ImGui::SetCursorPosX(msColTop.x);
-        ImGui::SetCursorPosY(std::max(msLeftBottomY, msRightBottomY));
-        availWidth = msFullWidth;
-    }
     ImGui::Dummy(ImVec2(0, gap));
 
     // ====================================================================