feat(ui): explain mining addresses everywhere and stop offering them for payment

Follow-up to 5246898. A transparent address only ever receives mining
rewards on DragonX (private chain), so:

- One explainer ("Receives solo-mining rewards only - the network rejects
  payments to it. Rewards are shielded automatically once they mature.")
  on the Overview row hover, the Receive picker hover, the Receive card
  and the Validate Address result (now typed "Mining address
  (transparent)").
- Receive: a selected mining address shows the explainer and a "Use a
  shielded address" button (creates one if none exists) instead of the
  payment request, and a "Not for payments" panel instead of a QR code.
  The default selection prefers a shielded address; the "All" filter
  hides empty mining addresses unless solo mining or marked as a mining
  address; the filter reads All / Shielded / Mining.
- Request Payment: no transparent section, never prefilled with one.
- Overview: no "Mining - Mining" tag on a marked transparent row.
- FAQ: address answers rewritten; the send and memo answers no longer
  imply you can pay a transparent address. All 8 languages.

i18n: 4 new keys, 6 FAQ answers updated in place, 2 dead keys removed,
CJK subset rebuilt. UI sweep: receive-mining-address and
modal-validate-mining targets.

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

scripts/add_missing_translations.py

@@ -25,6 +25,46 @@ def load_english_keys():
 
 # All translations for the 158 missing keys
 TRANSLATIONS = {
+    "mining_addr_explainer": {
+        "de": "Empfängt nur Solo-Mining-Belohnungen – das Netzwerk lehnt Zahlungen an diese Adresse ab. Belohnungen werden automatisch abgeschirmt, sobald sie gereift sind.",
+        "es": "Solo recibe recompensas de minería en solitario; la red rechaza los pagos a esta dirección. Las recompensas se blindan automáticamente cuando maduran.",
+        "fr": "Ne reçoit que des récompenses de minage en solo — le réseau refuse les paiements vers cette adresse. Les récompenses sont blindées automatiquement une fois arrivées à maturité.",
+        "pt": "Recebe apenas recompensas de mineração solo — a rede rejeita pagamentos para este endereço. As recompensas são blindadas automaticamente quando amadurecem.",
+        "ru": "Принимает только награды за соло-майнинг — сеть отклоняет платежи на этот адрес. Награды экранируются автоматически, когда созревают.",
+        "zh": "仅接收单人挖矿奖励——网络会拒绝向此地址付款。奖励成熟后会自动屏蔽。",
+        "ja": "ソロマイニング報酬のみを受け取ります。ネットワークはこのアドレスへの支払いを拒否します。報酬は成熟すると自動的にシールドされます。",
+        "ko": "솔로 채굴 보상만 받습니다. 네트워크가 이 주소로의 결제를 거부합니다. 보상은 성숙하면 자동으로 차폐됩니다.",
+    },
+    "receive_use_shielded": {
+        "de": "Abgeschirmte Adresse verwenden",
+        "es": "Usar una dirección blindada",
+        "fr": "Utiliser une adresse blindée",
+        "pt": "Usar um endereço blindado",
+        "ru": "Использовать экранированный адрес",
+        "zh": "使用屏蔽地址",
+        "ja": "シールドアドレスを使う",
+        "ko": "차폐 주소 사용",
+    },
+    "receive_not_for_payments": {
+        "de": "Nicht für Zahlungen",
+        "es": "No para pagos",
+        "fr": "Pas pour les paiements",
+        "pt": "Não é para pagamentos",
+        "ru": "Не для платежей",
+        "zh": "不用于付款",
+        "ja": "支払いには使えません",
+        "ko": "결제용이 아님",
+    },
+    "validate_mining_type": {
+        "de": "Mining-Adresse (transparent)",
+        "es": "Dirección de minería (transparente)",
+        "fr": "Adresse de minage (transparente)",
+        "pt": "Endereço de mineração (transparente)",
+        "ru": "Адрес для майнинга (прозрачный)",
+        "zh": "挖矿地址（透明）",
+        "ja": "マイニングアドレス（透明）",
+        "ko": "채굴 주소(투명)",
+    },
     "send_mining_addr_short": {
         "de": "Mining-Adresse – kann keine Zahlungen empfangen",
         "es": "Dirección de minería: no puede recibir pagos",