fix(mining): make "Est. Daily" honest about variance and fees

The mining "Est. Daily" was a solo expected-value (your hashrate share x
blocks/day x a fixed block reward) rendered in the same green as the real
Today / Yesterday / All-Time earnings, off an instantaneous hashrate and
gross of pool fees. It read like a dependable daily income when it is a
long-run statistical average with huge (Poisson) variance.

Framing:
- The estimate is now drawn in a neutral colour, not the green "money
  earned" colour (the actual mined totals stay green).
- A sub-label in BOTH modes marks it as an average ("avg", or "avg, net"
  in pool mode when the fee is applied), replacing the pool-only
  "before pool fee" note.
- A hover tooltip over the column explains the variance ("often nothing
  for long stretches, then a lump - NOT a steady daily income") and the
  fee status (after the N% fee / before the fee when unknown / nothing for
  solo and 0%-fee pools).

Accuracy:
- Uses a trailing-average hashrate instead of the instantaneous / 10s
  snapshot: pool prefers hashrate_15m (then 60s, then 10s); solo uses the
  mean of hashrate_history once there are >=10 samples, else the instant
  rate. This stops a spike or a momentary dip from swinging the figure.
- Subtracts the known pool fee so pool-mode figures are net; synthetic or
  unmatched pools stay gross and the tooltip says the fee is unknown.

The static block reward and true pool-reported earnings are intentionally
out of scope (the latter needs a new pool-API field). New i18n keys are
translated into all eight locales; the CJK subset font is rebuilt for the
three new glyphs. Builds + test suites pass on both variants.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

res/lang/zh.json

@@ -1308,6 +1308,8 @@
     "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_est_daily_sub": "平均",
+    "mining_est_daily_sub_net": "平均·净",
     "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",
@@ -2108,6 +2110,9 @@
     "tt_low_spec": "禁用所有重度视觉效果\\n快捷键：Ctrl+Shift+Down",
     "tt_merge": "将多个 UTXO 合并到一个地址",
     "tt_mine_idle": "系统空闲时自动开始挖矿\\n（无键盘/鼠标输入）",
+    "tt_mining_est_daily": "基于您当前在全网算力占比的长期统计平均值。实际挖矿奖励是随机到达的（泊松分布）——常常很长时间没有，然后一次性获得一笔，因此这并不是稳定的每日收入。",
+    "tt_mining_est_daily_fee_fmt": "已扣除 %.1f%% 矿池手续费。",
+    "tt_mining_est_daily_nofee": "未扣除矿池手续费（此矿池手续费未知）。",
     "tt_new_mining_address": "创建一个用于单人挖矿奖励的透明（R…）地址。它无法接收付款——收款请提供屏蔽地址。",
     "tt_noise": "颗粒纹理强度（0% = 关闭，100% = 最大）",
     "tt_open_app_dir": "在文件管理器中打开 ObsidianDragon 文件夹（设置、主题、日志）",