refactor(ui): consolidate dialog footers + shared empty-state, unify buttons/rounding

Addresses the cross-screen inconsistencies from the layout audit by routing screens onto
the design system's own (previously under-used) shared helpers:

- Dialog footers: migrate ~9 overlay dialogs off hand-rolled placement onto the shared
  helpers — DialogActionFooter (primary+Close), DialogConfirmFooter, or
  BeginOverlayDialogFooter for custom/multi-button rows — so footers share one centered
  treatment. All footer/action buttons now use TactileButton (glass press) instead of the
  bare StyledButton some dialogs used.
- Empty states: add a shared material::DrawEmptyState(icon, title, hint) (centered icon +
  title + wrapped hint) and adopt it in Peers, Transactions, and Market-portfolio, which
  previously showed a bare left-aligned caption.
- Security dialogs: add the missing Cancel to Change Passphrase and Set PIN so the whole
  security family shares a two-button footer (Cancel dismisses without applying).
- Transactions pager: shared TactileButton helpers (matching Explorer).
- Frosted-pane rounding: Contacts/Chat use Layout::glassRounding() instead of hardcoded
  12/10/8px literals, matching Peers.
- "Set Label..." title loses its stray trailing ellipsis.

Preserves every button's label and action; the transfer footer's order becomes
[Confirm][Cancel] to match the shared helper's primary-first convention. Verified at 1280
across full-node + Lite + Windows (ctest green) and an adversarial diff review (clean).

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

src/ui/windows/about_dialog.cpp

@@ -125,29 +125,26 @@ void RenderAboutDialog(App* app, bool* p_open)
     ImGui::Spacing();
     ImGui::TextWrapped("%s", TR("about_license_text"));
     
-    ImGui::Spacing();
-    ImGui::Separator();
-    ImGui::Spacing();
-    
-    // Links
-    if (material::StyledButton(TR("about_website"), ImVec2(linkW, 0), S.resolveFont(linkBtn.font))) {
+    // Links — 3-button action row, centered via the shared footer helper (draws its own
+    // Spacing/Separator/Spacing above the row, replacing the hand-rolled divider block).
+    const float linksTotalW = linkW * 3.0f + ImGui::GetStyle().ItemSpacing.x * 2.0f;
+    material::BeginOverlayDialogFooter(linksTotalW);
+    if (material::TactileButton(TR("about_website"), ImVec2(linkW, 0), S.resolveFont(linkBtn.font))) {
         util::Platform::openUrl("https://dragonx.is");
     }
     ImGui::SameLine();
-    if (material::StyledButton(TR("about_github"), ImVec2(linkW, 0), S.resolveFont(linkBtn.font))) {
+    if (material::TactileButton(TR("about_github"), ImVec2(linkW, 0), S.resolveFont(linkBtn.font))) {
         util::Platform::openUrl("https://git.dragonx.is/dragonx/ObsidianDragon");
     }
     ImGui::SameLine();
-    if (material::StyledButton(TR("about_block_explorer"), ImVec2(linkW, 0), S.resolveFont(linkBtn.font))) {
+    if (material::TactileButton(TR("about_block_explorer"), ImVec2(linkW, 0), S.resolveFont(linkBtn.font))) {
         util::Platform::openUrl("https://explorer.dragonx.is");
     }
-    
-    ImGui::Spacing();
-    
-    // Close button
-    float button_width = closeW;
-    ImGui::SetCursorPosX((ImGui::GetWindowWidth() - button_width) * 0.5f);
-    if (material::StyledButton(TR("close"), ImVec2(button_width, 0), S.resolveFont(closeBtn.font))) {
+
+    // Close button — lone dismiss action, centered via the shared footer helper (no extra
+    // divider above it, so it sits directly under the links row).
+    material::BeginOverlayDialogFooter(closeW, false);
+    if (material::TactileButton(TR("close"), ImVec2(closeW, 0), S.resolveFont(closeBtn.font))) {
         *p_open = false;
     }