fix(ui): scale unscaled geometry at HiDPI — inputs, send progress cards, chat/pool overlaps, peer rows

At font_scale 1.5 ~13 sites read absolute geometry (schema .size/.width) straight
into ImGui without ×dpiScale(), so they stayed native-size while the font grew and
overlapped/clipped real text or money:

- Shield/Merge fee + UTXO inputs, Request Payment amount, Block Info height input:
  ×dpiScale() so the value no longer clips (e.g. 0.00010000 -> 0.00010).
- Send: the confirm-popup Amount Details divider (floored the row step at the scaled
  caption height so it no longer strikes the Fee row), the tx-progress error and
  sending/success cards, and the zero-balance CTA button — all ×dp.
- Mining pool row: ellipsis-truncate the hostname so it can't collide with the
  right-aligned hashrate.
- Chat conversation list: scale the pane-width clamp AND clip the peer name to the
  column left of the timestamp (measure-then-clip) so name and time never overlap.
- Explorer block-detail label column, Peers row offsets, and DialogConfirmFooter
  button height — ×dp.

transaction_details keeps its negative fill-sentinel widths unscaled (a content
margin, not raw px). Verified at font_scale 1.5 across full-node + Lite + Windows
(ctest green) and an adversarial diff review (three wrong-scale regressions fixed).

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

src/ui/windows/explorer_tab.cpp

@@ -1116,8 +1116,9 @@ static void renderBlockDetailModal(App* app) {
 
     // ── Info grid ──
     ImDrawList* dl = ImGui::GetWindowDrawList();
+    float dp = Layout::dpiScale();
     float rowH = capFont->LegacySize + Layout::spacingXs() + sub1->LegacySize;
-    float labelW = S.drawElement("tabs.explorer", "label-column").size;
+    float labelW = S.drawElement("tabs.explorer", "label-column").size * dp;
     {
         ImVec2 gridPos = ImGui::GetCursorScreenPos();
         float gx = gridPos.x;