feat(ui): treat transparent addresses as mining-only addresses

DragonX is a private chain (-ac_private=1): consensus rejects any
non-coinbase output to a transparent address, so a t-address can only
ever receive mining rewards, and its coins can only move to a shielded
address. The wallet treated them like ordinary recipients.

Block paying one:
- Send: a transparent recipient shows "Mining address - can't be paid"
  and disables Review Send (tooltip explains; ask for a zs... address).
  Typing, paste, contacts and payment URIs all go through this field.
- Overview drag-to-transfer: a mining-address row is never a transfer
  target (it only reorders).
- Pool payout must be shielded (pools pay with ordinary transactions):
  field tooltip, disabled Start button and the start check say why.
- isValidRecipientAddress() is now shielded-only; new isDragonXAddress()
  and classifyRecipient() (Shielded / MiningOnly / Invalid).

Call them mining addresses:
- Overview: "Mining rewards" card (amber "Not yet shielded" when there
  is a balance; hover explains; click opens the Shield dialog), "New
  mining address" button with a tooltip, rows typed "Mining".
- QR / label dialogs, portfolio filter, contact badge ("Mining only"),
  Receive notifications.

i18n: 17 new keys in all 8 languages, 12 dead keys removed, CJK subset
rebuilt. Tests: recipient classification, translation completeness.
UI sweep: new "send-mining-recipient" target.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ui/windows/balance_tab.cpp

@@ -12,6 +12,7 @@
 #include "qr_popup_dialog.h"
 #include "address_label_dialog.h"
 #include "address_transfer_dialog.h"
+#include "shield_dialog.h"
 #include "send_tab.h"
 #include "../../app.h"
 #include "../../config/settings.h"
@@ -531,7 +532,7 @@ static void RenderBalanceClassic(App* app)
             float cy = cMin.y + cardPadLg;
 
             dl->AddText(ovFont, ovFont->LegacySize, ImVec2(cx, cy),
-                        OnSurfaceMedium(), TR("transparent"));
+                        OnSurfaceMedium(), TR("mining_rewards"));
             cy += ovFont->LegacySize + ovGap;
 
             snprintf(buf, sizeof(buf), "%.8f", s_dispTransparent);
@@ -543,18 +544,24 @@ static void RenderBalanceClassic(App* app)
                         OnSurfaceMedium(), DRAGONX_TICKER);
             cy += sub1->LegacySize + valGap;
 
-            snprintf(buf, sizeof(buf), TR("baltab_t_addresses_count"),
-                     (int)state.t_addresses.size());
+            // Rewards waiting at a mining address: say so, and let a click shield them now.
+            const bool unshielded = s_dispTransparent > 0.0;
+            if (unshielded) snprintf(buf, sizeof(buf), "%s", TR("mining_rewards_unshielded"));
+            else snprintf(buf, sizeof(buf), TR("baltab_mining_addresses_count"), (int)state.t_addresses.size());
             dl->AddText(capFont, capFont->LegacySize, ImVec2(cx, cy),
-                        OnSurfaceDisabled(), buf);
+                        unshielded ? amberCol : OnSurfaceDisabled(), buf);
 
-            // Hover glow + click to Receive
+            // Hover glow + explain; click shields waiting rewards (else opens Receive)
             if (material::IsRectHovered(cMin, cMax)) {
                 dl->AddRect(cMin, cMax, IM_COL32(255, 255, 255, (int)S.drawElement("tabs.balance", "hover-glow-alpha").sizeOr(40.0f)),
                             cardSpec.rounding, 0, S.drawElement("tabs.balance", "hover-glow-thickness").sizeOr(1.5f) * dp);
                 ImGui::SetMouseCursor(ImGuiMouseCursor_Hand);
-                if (ImGui::IsMouseClicked(0))
-                    app->setCurrentPage(NavPage::Receive);
+                material::Tooltip("%s%s%s", TR("mining_card_tooltip"), unshielded ? "\n\n" : "",
+                                  unshielded ? TR("mining_card_click_to_shield") : "");
+                if (ImGui::IsMouseClicked(0)) {
+                    if (unshielded) ShieldDialog::showShieldCoinbase();
+                    else app->setCurrentPage(NavPage::Receive);
+                }
             }
         }
 
@@ -803,7 +810,7 @@ static void RenderBalanceDonut(App* app) {
 
         // Transparent legend
         dl->AddCircleFilled(ImVec2(legendX + 5 * dp, legendY + capFont->LegacySize * 0.5f), legendDotR, Warning());
-        snprintf(buf, sizeof(buf), TR("baltab_transparent_amount"), s_dispTransparent);
+        snprintf(buf, sizeof(buf), TR("baltab_mining_amount"), s_dispTransparent);
         dl->AddText(capFont, capFont->LegacySize, ImVec2(legendX + legendXOff, legendY), Warning(), buf);
         legendY += capFont->LegacySize + legendSectionGap;
 
@@ -976,7 +983,7 @@ static void RenderBalanceConsolidated(App* app) {
     // Transparent bar
     float transX = cardMin.x + pad * 2 + halfW;
     barY = divY + Layout::spacingSm();
-    std::string transLabelUpper = TR("transparent");
+    std::string transLabelUpper = TR("mining_rewards");
     std::transform(transLabelUpper.begin(), transLabelUpper.end(), transLabelUpper.begin(),
                    [](unsigned char c){ return (char)std::toupper(c); });
     dl->AddText(ovFont, ovFont->LegacySize, ImVec2(transX, barY), Warning(), transLabelUpper.c_str());
@@ -1100,7 +1107,7 @@ static void RenderBalanceDashboard(App* app) {
         std::transform(s.begin(), s.end(), s.begin(), [](unsigned char c){ return (char)std::toupper(c); });
         return s;
     };
-    std::string lblShielded = upperTR("shielded"), lblTransparent = upperTR("transparent");
+    std::string lblShielded = upperTR("shielded"), lblTransparent = upperTR("mining_rewards");
     std::string lblQuickSend = upperTR("quick_send"), lblQuickReceive = upperTR("quick_receive");
 
     TileInfo tiles[4] = {
@@ -1240,7 +1247,7 @@ static void RenderBalanceVerticalStack(App* app) {
     RowInfo rowInfos[4] = {
         {TR("baltab_total_balance"), ICON_MD_ACCOUNT_BALANCE_WALLET, S.resolveColor("var(--accent-total)", OnSurface()), s_dispTotal, 1.0f},
         {TR("baltab_shielded"), ICON_MD_SHIELD, S.resolveColor("var(--accent-shielded)", Success()), s_dispShielded, shieldRatio},
-        {TR("baltab_transparent"), ICON_MD_CIRCLE, S.resolveColor("var(--accent-transparent)", Warning()), s_dispTransparent, transRatio},
+        {TR("mining_rewards"), ICON_MD_CIRCLE, S.resolveColor("var(--accent-transparent)", Warning()), s_dispTransparent, transRatio},
         {TR("baltab_market"), ICON_MD_TRENDING_UP, S.resolveColor("var(--accent-action)", Primary()), state.market.price_usd, 0.0f},
     };
 
@@ -1437,7 +1444,7 @@ static void RenderBalanceVertical2x2(App* app) {
         // Row 1: Market (left), Transparent (right)
         {
             {TR("baltab_market"), ICON_MD_TRENDING_UP, S.resolveColor("var(--accent-action)", Primary()), state.market.price_usd, 0.0f, true, false},
-            {TR("baltab_transparent"), ICON_MD_CIRCLE, S.resolveColor("var(--accent-transparent)", Warning()), s_dispTransparent, transRatio, false, true},
+            {TR("mining_rewards"), ICON_MD_CIRCLE, S.resolveColor("var(--accent-transparent)", Warning()), s_dispTransparent, transRatio, false, true},
         },
     };
 
@@ -1696,7 +1703,7 @@ static void RenderBalanceShield(App* app) {
         std::string shieldLabelUpper = TR("shielded");
         std::transform(shieldLabelUpper.begin(), shieldLabelUpper.end(), shieldLabelUpper.begin(),
                        [](unsigned char c){ return (char)std::toupper(c); });
-        std::string transLabelUpper = TR("transparent");
+        std::string transLabelUpper = TR("mining_rewards");
         std::transform(transLabelUpper.begin(), transLabelUpper.end(), transLabelUpper.begin(),
                        [](unsigned char c){ return (char)std::toupper(c); });
         dl->AddText(ovFont, ovFont->LegacySize, ImVec2(infoX, infoY), Success(), shieldLabelUpper.c_str());
@@ -1855,7 +1862,7 @@ static void RenderBalanceTimeline(App* app) {
             std::transform(s.begin(), s.end(), s.begin(), [](unsigned char c){ return (char)std::toupper(c); });
             return s;
         };
-        std::string cShielded = upperTR("shielded"), cTransparent = upperTR("transparent"), cMarket = upperTR("market");
+        std::string cShielded = upperTR("shielded"), cTransparent = upperTR("mining_rewards"), cMarket = upperTR("market");
         SumCard cards[3] = {
             {cShielded.c_str(), Success(), s_dispShielded, false},
             {cTransparent.c_str(), Warning(), s_dispTransparent, false},
@@ -2137,7 +2144,7 @@ static void RenderBalanceMinimal(App* app) {
     snprintf(buf, sizeof(buf), TR("balance_shielded_fmt"), s_dispShielded);
     Type().textColored(TypeStyle::Caption, Success(), buf);
     ImGui::SameLine(0, Layout::spacingLg());
-    snprintf(buf, sizeof(buf), TR("balance_transparent_fmt"), s_dispTransparent);
+    snprintf(buf, sizeof(buf), TR("balance_mining_fmt"), s_dispTransparent);
     Type().textColored(TypeStyle::Caption, Warning(), buf);
 
     // USD value