feat(ui): float the remaining large dialogs (Phase 2 float rollout)

Per the user's selection, convert the large multi-section dialogs to the BlurFloat
style (floating content on the blur, plain heading, no glass card), each KEEPING
its authored width so width-coupled content is untouched:
- Export all keys, Console RPC reference, Explorer block detail
- Updater dialogs: daemon update, xmrig update, bootstrap download (multi-state)

Settings and Address book intentionally kept as cards (the modal Settings *window*
is dead code — show_settings_ is never set; the live Settings surface is the nav
page, not a modal; Address book has a nested edit that reads better contained).
All other confirm/input dialogs stay card-on-blur ("card for small"). Updater
dialogs are multi-state — GUI-check each state (confirm/progress/done/failed).

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

src/ui/windows/bootstrap_download_dialog.h

@@ -53,7 +53,10 @@ public:
         using namespace material;
         const float dp = Layout::dpiScale();
 
-        if (BeginOverlayDialog(TR("download_bootstrap"), &s_open, 500.0f, 0.94f)) {
+        OverlayDialogSpec ov;
+        ov.title = TR("download_bootstrap"); ov.p_open = &s_open;
+        ov.style = OverlayStyle::BlurFloat; ov.cardWidth = 500.0f; ov.cardBottomViewportRatio = 0.94f;
+        if (BeginOverlayDialog(ov)) {
 
             if (s_state == State::Confirm) {
                 renderConfirm(dp);