feat(ui): layout polish — fill dead space, pair/box/collapse, warning weight, dialog glass

Implements the layout-improvement suggestions from the layout audit (visual arrangement
only; no functionality added or removed):

- Send/Receive: the recent-activity list now grows to fill the space below the fixed
  compose/receive card (more history visible), with a centered empty-state when there is
  none — instead of leaving dead canvas.
- Shield/Merge: pair the Fee and UTXO-Limit fields on one row to tighten vertical rhythm.
- Market: extend + frame the portfolio group-list as one contained panel (with a bottom
  edge) and center its empty-state, closing the previously un-anchored gap.
- Overlay dialogs: raise the card glass fill/border alpha (35/50 -> 60/90 of 255) so the
  dialog card reads as a distinct surface over busy backdrops (global, all overlays).
- Wallets: size the list height to the actual wallet count instead of always reserving 7
  rows, removing the large gap before the scan/create prompts (still scrolls when many).
- Contacts: width-aware address truncation shows more of the address on wide rows.
- Transfer Funds: give the "sends the full balance" warning a warning icon + color so the
  stakes stand out from the neutral result-preview lines.
- First-run wizard: collapse a completed Step 1 (Appearance) to the compact pill like
  Step 2, so a finished step is no longer taller than the active one.
- Explorer: distribute the Chain card's two stats to match the density of the sibling
  metrics grid.
- Validate Address: a "Results will appear here" caption fills the pre-interaction blank.
- Change Passphrase: add the warning banner its sibling security dialogs have.
- Migration ShowSeed: box the 24-word mnemonic grid (a GlassSectionScope behind the
  existing RenderSeedWordGrid) so the critical secret reads as a distinct artifact —
  purely visual, no seed/logic/state change.

Verified at 1280 across full-node + Lite + Windows (ctest green) and an adversarial diff
review (clean). New i18n key backfilled into all 8 languages.

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

src/ui/windows/receive_tab.cpp

@@ -362,9 +362,14 @@ static void RenderRecentReceived(const AddressInfo& /* addr */,
         if (tx.type != "receive" && tx.type != "mined") continue;
         recvs.push_back(&tx);
     }
-    if (recvs.size() > 4) recvs.resize(4);  // show only the 4 most recent (newest-first)
 
+    // Grow the list to fill the dead space beneath the (fixed-height) receive card:
+    // fit as many newest-first rows as the remaining region can show, instead of a
+    // fixed 4. The child scrolls if the real history exceeds what fits, so nothing is
+    // lost. A floor of 4 keeps the section substantial when the region is short.
     float listH = std::max(rowH, ImGui::GetContentRegionAvail().y);
+    size_t maxRows = std::max<size_t>(4, (size_t)std::floor(listH / rowH));
+    if (recvs.size() > maxRows) recvs.resize(maxRows);  // newest-first
 
     ImGui::BeginChild("##RecentReceivedRows", ImVec2(width, listH), false,
         ImGuiWindowFlags_NoBackground);
@@ -372,8 +377,9 @@ static void RenderRecentReceived(const AddressInfo& /* addr */,
 
     char buf[64];
     if (recvs.empty()) {
-        ImGui::SetCursorPosY(Layout::spacingMd());
-        Type().textColored(TypeStyle::Caption, OnSurfaceDisabled(), TR("no_recent_receives"));
+        // Fill the empty canvas with a centered material empty-state (icon + title)
+        // rather than a lone left-aligned caption stranded at the top of dead space.
+        material::DrawEmptyState(ICON_MD_CALL_RECEIVED, TR("no_recent_receives"));
         ImGui::EndChild();
         return;
     }