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/market_tab.cpp

@@ -2136,11 +2136,29 @@ static void mktDrawPortfolio(const MktCtx& cx)
         float rowGap = pfRowGapFor(style, mktDp);
         float rowsH = std::max(rowH, portfolioH - pfSummaryH);
 
+        // Anchor the bottom of the portfolio: the group list otherwise ends at its content height,
+        // leaving un-anchored dead space between the last row and the content-area bottom. Grow the
+        // rows region to fill the remaining vertical space (down to the scroll area's bottom, less a
+        // small margin) and wrap it in a contained glass panel — so it reads as one framed table with
+        // a real bottom edge (like Explorer's block-list card) instead of trailing off into nothing.
+        // The empty state then centres in this full-height panel rather than in a one-row band.
         ImGui::SetCursorScreenPos(ImVec2(cardMin.x, cardMin.y + pfSummaryH));
+        float floorH = ImGui::GetContentRegionAvail().y - gap;   // to the scroll bottom, keep a margin
+        float panelH = std::max(rowsH, floorH);
+        {
+            ImVec2 pMin(cardMin.x, cardMin.y + pfSummaryH);
+            ImVec2 pMax(rightEdge, pMin.y + panelH);
+            GlassPanelSpec pg;
+            pg.rounding = Layout::glassRounding();
+            pg.fillAlpha = 12; pg.borderAlpha = 24;   // faint container: frames without competing with the per-row cards
+            DrawGlassPanel(dl, pMin, pMax, pg);
+        }
         // Flush-left child (no window padding) so rows align with the summary; a scrollbar appears
-        // only when the visible groups overflow the bounded height.
+        // only when the visible groups overflow the bounded height. NoBackground so the contained
+        // glass panel drawn above is the sole surface — otherwise the opaque ChildBg (non-acrylic
+        // mode) would paint over the panel fill + border.
         ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0, 0));
-        ImGui::BeginChild("##pfRows", ImVec2(availWidth, rowsH), false);
+        ImGui::BeginChild("##pfRows", ImVec2(availWidth, panelH), false, ImGuiWindowFlags_NoBackground);
         ImGui::PopStyleVar();
         // Zero item-spacing INSIDE the child: each row emits an InvisibleButton + a gap Dummy, and
         // ImGui's default ItemSpacing.y between those items would inflate the content past rowsH and