feat: ATR adaptive trailing stop and 2-decimal formatting

- monitor.py: replace fixed 1.5% stop with ATR-based adaptive stop
  recent 5x 1h candles avg range × 1.5 mult, clamped 1.0%~4.0%
  10min cache per ticker to minimize API calls
  all log numbers formatted to 2 decimal places
- notify.py: apply 2 decimal places to price, P&L, fee, cum_profit

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

core/notify.py

@@ -38,9 +38,9 @@ def notify_buy(
     )
     _send(
         f"📈 <b>[매수]</b> {ticker}\n"
-        f"가격: {price:,.0f}원\n"
-        f"수량: {amount}\n"
-        f"투자금: {invested_krw:,}원\n"
+        f"가격: {price:,.2f}원\n"
+        f"수량: {amount:.8f}\n"
+        f"투자금: {invested_krw:,.2f}원\n"
         f"{budget_line}"
     )
 
@@ -54,10 +54,10 @@ def notify_sell(
     cum_emoji   = "💚" if cum_profit >= 0 else "🔴"
     _send(
         f"{trade_emoji} <b>[매도]</b> {ticker}\n"
-        f"가격: {price:,.0f}원\n"
+        f"가격: {price:,.2f}원\n"
         f"수익률: {pnl_pct:+.2f}%\n"
-        f"실손익: {krw_profit:+,.0f}원 (수수료 {fee_krw:,.0f}원)\n"
-        f"{cum_emoji} 누적손익: {cum_profit:+,.0f}원\n"
+        f"실손익: {krw_profit:+,.2f}원 (수수료 {fee_krw:,.2f}원)\n"
+        f"{cum_emoji} 누적손익: {cum_profit:+,.2f}원\n"
         f"사유: {reason}"
     )
 
@@ -120,9 +120,9 @@ def notify_status(
         emoji = "📈" if pnl >= 0 else "📉"
         lines.append(
             f"{emoji} <b>{ticker}</b>\n"
-            f"  현재가: {current:,.0f}원\n"
+            f"  현재가: {current:,.2f}원\n"
             f"  수익률: {pnl:+.2f}%\n"
-            f"  최고가 대비: -{drop:.1f}%\n"
-            f"  보유: {elapsed:.1f}h"
+            f"  최고가 대비: -{drop:.2f}%\n"
+            f"  보유: {elapsed:.2f}h"
         )
     _send("\n".join(lines))