feat(ui): implement UI/UX audit — i18n, HiDPI, theme, destructive-action & overflow fixes

Implements all 26 confirmed UI/UX audit findings plus the 4 dashboard/timeline
tile labels. Verified across full-node + Lite + Windows builds (ctest green) and
an adversarial diff review (one market-tab delete regression caught + fixed).

i18n coverage:
- Balance hero/quick-actions/toasts + dashboard & timeline tiles (Total Balance,
  Shielded, Transparent, Quick Send, Quick Receive, Click to open, Market)
- Send: Review Send / Cancel / Paste / view-only tooltip / memo byte counter
- Settings: Lite lifecycle errors, plaintext-RPC security warning, 8 toasts
- Mining pool-payout tooltip
- Resolve daemon_update_title double-assignment collision (new daemon_update_prompt_title)
- 23 new keys translated into all 8 locales; CJK subset font rebuilt

HiDPI: DPI-scale the Send amount bar, mining thread-tile clamp bounds, receive
loading skeleton, and sidebar notification-badge insets.

Light theme: theme-aware material::SurfaceOverlay() for balance bar tracks and
row-hover highlights; contacts active-pill foreground uses OnPrimary().

Destructive actions: arm/confirm for portfolio-group delete, saved pool/worker
remove, and avatar-image delete.

Interaction/overflow: route balance star/eye buttons and the console fold-toggle
through popup-safe guards; clip peer addr/subver; truncate the balance custom
label; measure Settings tool-button widths; mining stepper disabled-state
feedback; +/- stepper buttons restyled to match the thread tiles.

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

src/ui/material/colors.h

@@ -116,6 +116,26 @@ inline ImVec4 WarningVec4()        { return ImGui::ColorConvertU32ToFloat4(Warni
 // Convenience Functions for Common Patterns
 // ============================================================================
 
+/**
+ * @brief Theme-aware translucent overlay for tracks / hover fills / dividers.
+ *
+ * A raw white overlay (IM_COL32(255,255,255,a)) reads on dark skins but vanishes
+ * on light/pastel skins (white-on-white). This picks a dark overlay on light
+ * themes and a white overlay on dark themes so the alpha reads either way.
+ * (Self-contained luminance check so colors.h stays free of draw_helpers.h.)
+ *
+ * @param alpha 0-255 opacity of the overlay
+ */
+inline ImU32 SurfaceOverlay(int alpha)
+{
+    ImU32 bg = Background();
+    float r = ((bg >> IM_COL32_R_SHIFT) & 0xFF) / 255.0f;
+    float g = ((bg >> IM_COL32_G_SHIFT) & 0xFF) / 255.0f;
+    float b = ((bg >> IM_COL32_B_SHIFT) & 0xFF) / 255.0f;
+    bool light = (0.299f * r + 0.587f * g + 0.114f * b) > 0.5f;
+    return light ? IM_COL32(0, 0, 0, alpha) : IM_COL32(255, 255, 255, alpha);
+}
+
 /**
  * @brief Get color with applied state overlay
  *