fix(modals): a fixed-card modal can no longer wheel-scroll as a whole

The overlay content child had NoScrollbar (hides the scrollbar) but not
NoScrollWithMouse — so when a fixed-height card's content overflowed by even a
few px, the mouse wheel silently drifted the ENTIRE dialog (title + panes +
footer). Add NoScrollWithMouse to the content child: a modal is a fixed frame;
inner scroll regions (version list, release notes, command list) still scroll on
their own, and auto-height cards resize to content so they never overflow.

Also fix the daemon updater's footer budget, which under-counted the
Spacing/Separator/Spacing + inter-item gaps and produced exactly that few-px
overflow. Verified daemon / console / wallets / portfolio render intact.

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

src/ui/material/draw_helpers.h

@@ -1476,9 +1476,13 @@ inline bool BeginOverlayDialog(const OverlayDialogSpec& spec)
     ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, floating ? ImVec2(28, 20) : ImVec2(28, 24));
     ImGui::PushStyleColor(ImGuiCol_ChildBg, ImVec4(0, 0, 0, 0));  // transparent (glass/blur behind)
     ImGuiChildFlags cflags = ImGuiChildFlags_AlwaysUseWindowPadding | (fixedHeight ? 0 : ImGuiChildFlags_AutoResizeY);
+    // NoScrollWithMouse (not just NoScrollbar): a modal is a fixed frame — the wheel must never drift
+    // the WHOLE card. If content marginally overflows a fixed card, the wheel would otherwise scroll
+    // the entire dialog (title + footer and all). Inner scroll regions (lists, notes) still scroll on
+    // their own; auto-height cards resize to content so they never overflow anyway.
     bool childVisible = ImGui::BeginChild(childId.c_str(),
         ImVec2(cardWidth, fixedHeight ? (cardBottomY - cardY) : 0.0f),
-        cflags, ImGuiWindowFlags_NoScrollbar);
+        cflags, ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoScrollWithMouse);
     // Floating (portfolio-style) cards: the padding applies to this content child only, so pop it
     // now (nested children mustn't inherit it), and center button labels. Net style-var count stays
     // at 2 (ChildRounding + ButtonTextAlign) so EndOverlayDialog's PopStyleVar(2) is unchanged.

src/ui/windows/daemon_download_dialog.h

@@ -226,7 +226,12 @@ private:
         ImFont* capF  = Type().caption();
 
         const bool showFooter = (p.state == St::ReleaseList);
-        const float footerH = showFooter ? (ImGui::GetFrameHeight() + Layout::spacingSm() * 2.0f + 1.0f) : 0.0f;
+        // Budget the whole footer block — the Spacing + Separator + Spacing + button row and every
+        // inter-item gap — so the two-pane body leaves exact room and nothing overflows the card.
+        const float footerH = showFooter
+            ? (ImGui::GetFrameHeightWithSpacing() + ImGui::GetStyle().ItemSpacing.y * 3.0f
+               + Layout::spacingSm() * 2.0f + 1.0f)
+            : 0.0f;
         const float bodyH   = std::max(120.0f * dp, ImGui::GetContentRegionAvail().y - footerH);
         const float contentW = ImGui::GetContentRegionAvail().x;
         const float gap = Layout::spacingLg();