fix(mining): remediate mining-tab audit (22 findings) — crash-safety, async control, validation, math

Fixes all 22 confirmed findings from the mining-tab audit (10 Medium, 12 Low; 0 Critical/High),
adversarially reviewed (6 follow-ups found + fixed, incl. the review-caught idle-auto-start bypass
and a wrong benchmark-restore condition).

Crash-safety & lifecycle:
- M-04: join a stale/finished monitor thread in XmrigManager::start() and ~XmrigManager so an xmrig
  crash-then-restart (or quit) no longer std::terminate()s the wallet.
- L-03/L-10: surface an unexpected miner exit once and clear the stale running flag.

UI never blocks (M-03/L-06/L-08/L-09/L-13): pool start/stop now run on a dedicated serialized FIFO
mining-control thread (joined before teardown), so the ~13 call sites don't block the render thread on
stop()'s SIGTERM->SIGKILL->join; the spawn result marshals back to the UI.

Miner-process / pool trust boundary:
- M-01: validate the payout address (util::isValidRecipientAddress) at EVERY start path — the UI gate
  AND App::startPoolMining() (idle auto-start / thread scaling) — so a stale/wrong-chain address can't
  silently lose rewards.
- M-09: SSRF guard skips the background pool-stats GET for loopback/private/link-local/single-label hosts.
- M-02/L-02: cap the pool-stats + xmrig-API HTTP response bodies.
- L-01: write the xmrig config 0600 at creation (POSIX open with mode) — no world/group-readable window.
- M-10: reject shell-metacharacter binary paths before the version popen (excluding '()' so Program Files
  (x86) still works).

Solo mining: M-06/M-08 clamp thread count to [1, cores] at the setgenerate/xmrig boundary; M-07 notify +
don't lie on stop failure.

Correctness: L-05 block-time constant 75->150s (chainparams); M-05 discloses pool-mode "Est. Daily" as a
rough solo-equivalent; L-04/L-11/L-12 benchmark lifecycle (cancel on nav-away / mode-switch with restore,
skip rebalance mid-benchmark); L-07 honor cancel mid-extract in both the xmrig and daemon updaters.

Two new i18n keys back-filled across all 8 languages; CJK subset font rebuilt for the new glyphs.
Verified across full-node, lite, and Windows builds; tests pass.

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

res/lang/de.json

@@ -886,6 +886,7 @@
     "mining_difficulty_copied": "Schwierigkeit kopiert",
     "mining_est_block": "Gesch. Block",
     "mining_est_daily": "Gesch. täglich",
+    "mining_est_daily_pool_sub": "grobe Solo-Äquivalenz, vor Pool-Gebühr",
     "mining_filter_all": "Alle",
     "mining_filter_tip_all": "Alle Einnahmen anzeigen",
     "mining_filter_tip_pool": "Nur Pool-Einnahmen anzeigen",
@@ -914,6 +915,7 @@
     "mining_open_in_explorer": "Im Explorer öffnen",
     "mining_payout_address": "Auszahlungsadresse",
     "mining_payout_foreign": "⚠ Diese Auszahlungsadresse befindet sich nicht in Ihrer aktuellen Wallet — geschürfte Belohnungen würden an eine andere Wallet gehen. Aktualisieren Sie sie, wenn Sie die Wallet gewechselt haben.",
+    "mining_payout_invalid": "Keine gültige DragonX-Adresse — vor dem Start korrigieren, sonst gehen die Mining-Belohnungen verloren.",
     "mining_payout_tooltip": "Adresse für Mining-Belohnungen",
     "mining_pool": "Pool",
     "mining_pool_fee": "Gebühr",

res/lang/es.json

@@ -886,6 +886,7 @@
     "mining_difficulty_copied": "Dificultad copiada",
     "mining_est_block": "Bloque Est.",
     "mining_est_daily": "Diario Est.",
+    "mining_est_daily_pool_sub": "equivalente solo aproximado, antes de la comisión del pool",
     "mining_filter_all": "Todos",
     "mining_filter_tip_all": "Mostrar todas las ganancias",
     "mining_filter_tip_pool": "Mostrar solo ganancias del pool",
@@ -914,6 +915,7 @@
     "mining_open_in_explorer": "Abrir en explorador",
     "mining_payout_address": "Dirección de Pago",
     "mining_payout_foreign": "⚠ Esta dirección de pago no está en tu cartera actual — las recompensas minadas irían a otra cartera. Actualízala si cambiaste de cartera.",
+    "mining_payout_invalid": "No es una dirección DragonX válida — corrígela antes de empezar, o se pierden las recompensas de minería.",
     "mining_payout_tooltip": "Dirección para recibir recompensas de minería",
     "mining_pool": "Pool",
     "mining_pool_fee": "Comisión",

res/lang/fr.json

@@ -886,6 +886,7 @@
     "mining_difficulty_copied": "Difficulté copiée",
     "mining_est_block": "Bloc est.",
     "mining_est_daily": "Est. quotidien",
+    "mining_est_daily_pool_sub": "équivalent solo approximatif, avant les frais du pool",
     "mining_filter_all": "Tout",
     "mining_filter_tip_all": "Afficher tous les gains",
     "mining_filter_tip_pool": "Afficher uniquement les gains du pool",
@@ -914,6 +915,7 @@
     "mining_open_in_explorer": "Ouvrir dans l'explorateur",
     "mining_payout_address": "Adresse de paiement",
     "mining_payout_foreign": "⚠ Cette adresse de paiement ne fait pas partie de votre portefeuille actuel — les récompenses minées iraient vers un autre portefeuille. Mettez-la à jour si vous avez changé de portefeuille.",
+    "mining_payout_invalid": "Adresse DragonX invalide — corrigez-la avant de démarrer, sinon les récompenses de minage sont perdues.",
     "mining_payout_tooltip": "Adresse pour recevoir les récompenses de minage",
     "mining_pool": "Pool",
     "mining_pool_fee": "Frais",

res/lang/ja.json

@@ -886,6 +886,7 @@
     "mining_difficulty_copied": "難易度をコピーしました",
     "mining_est_block": "予測ブロック",
     "mining_est_daily": "予測日収",
+    "mining_est_daily_pool_sub": "おおよそのソロ換算（プール手数料前）",
     "mining_filter_all": "すべて",
     "mining_filter_tip_all": "すべての収益を表示",
     "mining_filter_tip_pool": "プール収益のみ表示",
@@ -914,6 +915,7 @@
     "mining_open_in_explorer": "エクスプローラーで開く",
     "mining_payout_address": "支払いアドレス",
     "mining_payout_foreign": "⚠ この支払いアドレスは現在のウォレットに含まれていません — マイニング報酬が別のウォレットに送られます。ウォレットを切り替えた場合は更新してください。",
+    "mining_payout_invalid": "有効な DragonX アドレスではありません — 開始前に修正してください。さもないとマイニング報酬が失われます。",
     "mining_payout_tooltip": "マイニング報酬の受取アドレス",
     "mining_pool": "プール",
     "mining_pool_fee": "手数料",

res/lang/ko.json

@@ -885,6 +885,7 @@
     "mining_difficulty_copied": "난이도가 복사되었습니다",
     "mining_est_block": "예상 블록",
     "mining_est_daily": "예상 일일 수익",
+    "mining_est_daily_pool_sub": "대략적인 솔로 환산, 풀 수수료 전",
     "mining_filter_all": "전체",
     "mining_filter_tip_all": "모든 수익 표시",
     "mining_filter_tip_pool": "풀 수익만 표시",
@@ -913,6 +914,7 @@
     "mining_open_in_explorer": "탐색기에서 열기",
     "mining_payout_address": "지급 주소",
     "mining_payout_foreign": "⚠ 이 지급 주소는 현재 지갑에 없습니다 — 채굴한 보상이 다른 지갑으로 전송됩니다. 지갑을 전환했다면 주소를 업데이트하세요.",
+    "mining_payout_invalid": "유효한 DragonX 주소가 아닙니다 — 시작하기 전에 수정하세요. 그렇지 않으면 채굴 보상이 사라집니다.",
     "mining_payout_tooltip": "채굴 보상 수신 주소",
     "mining_pool": "풀",
     "mining_pool_fee": "수수료",

res/lang/pt.json

@@ -886,6 +886,7 @@
     "mining_difficulty_copied": "Dificuldade copiada",
     "mining_est_block": "Bloco Est.",
     "mining_est_daily": "Est. Diário",
+    "mining_est_daily_pool_sub": "equivalente solo aproximado, antes da taxa do pool",
     "mining_filter_all": "Todos",
     "mining_filter_tip_all": "Mostrar todos os ganhos",
     "mining_filter_tip_pool": "Mostrar apenas ganhos do pool",
@@ -914,6 +915,7 @@
     "mining_open_in_explorer": "Abrir no explorador",
     "mining_payout_address": "Endereço de Pagamento",
     "mining_payout_foreign": "⚠ Este endereço de pagamento não está na sua carteira atual — as recompensas mineradas iriam para uma carteira diferente. Atualize-o se você trocou de carteira.",
+    "mining_payout_invalid": "Endereço DragonX inválido — corrija antes de iniciar, ou as recompensas de mineração serão perdidas.",
     "mining_payout_tooltip": "Endereço para receber recompensas de mineração",
     "mining_pool": "Pool",
     "mining_pool_fee": "Taxa",

res/lang/ru.json

@@ -886,6 +886,7 @@
     "mining_difficulty_copied": "Сложность скопирована",
     "mining_est_block": "Расч. блок",
     "mining_est_daily": "Расч. за день",
+    "mining_est_daily_pool_sub": "примерный соло-эквивалент, до комиссии пула",
     "mining_filter_all": "Все",
     "mining_filter_tip_all": "Показать все доходы",
     "mining_filter_tip_pool": "Показать только доходы пула",
@@ -914,6 +915,7 @@
     "mining_open_in_explorer": "Открыть в обозревателе",
     "mining_payout_address": "Адрес выплат",
     "mining_payout_foreign": "⚠ Этот адрес выплат отсутствует в вашем текущем кошельке — намайненные вознаграждения будут отправлены в другой кошелёк. Обновите его, если вы сменили кошелёк.",
+    "mining_payout_invalid": "Недействительный адрес DragonX — исправьте перед запуском, иначе награды за майнинг будут потеряны.",
     "mining_payout_tooltip": "Адрес для получения вознаграждений за майнинг",
     "mining_pool": "Пул",
     "mining_pool_fee": "Комиссия",

res/lang/zh.json

@@ -885,6 +885,7 @@
     "mining_difficulty_copied": "难度已复制",
     "mining_est_block": "预计区块",
     "mining_est_daily": "预计日收益",
+    "mining_est_daily_pool_sub": "粗略的单人挖矿等值，扣除矿池费用前",
     "mining_filter_all": "全部",
     "mining_filter_tip_all": "显示所有收益",
     "mining_filter_tip_pool": "仅显示矿池收益",
@@ -913,6 +914,7 @@
     "mining_open_in_explorer": "在浏览器中打开",
     "mining_payout_address": "支付地址",
     "mining_payout_foreign": "⚠ 此支付地址不在您当前的钱包中——挖矿奖励将进入另一个钱包。如果您切换过钱包，请更新它。",
+    "mining_payout_invalid": "不是有效的 DragonX 地址——启动前请更正，否则挖矿奖励将丢失。",
     "mining_payout_tooltip": "接收挖矿奖励的地址",
     "mining_pool": "矿池",
     "mining_pool_fee": "费用",