fix: persist sell prices to DB and add WF filter bootstrap

- price_db: add sell_prices table (ensure/upsert/load/delete)
- trader: restore _last_sell_prices from DB on startup so re-entry
  block survives restarts; persist each sell price immediately
- market: retry chunk requests up to 3 times with backoff on 429

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

core/market.py

@@ -29,15 +29,27 @@ def get_top_tickers() -> list[str]:
         if not all_tickers:
             return []
 
-        # 100개씩 나눠서 조회 (URL 길이 제한)
+        # 100개씩 나눠서 조회 (URL 길이 제한, 429 재시도 포함)
         chunk_size = 100
         ticker_data = []
         for i in range(0, len(all_tickers), chunk_size):
             chunk = all_tickers[i:i + chunk_size]
             params = {"markets": ",".join(chunk)}
-            resp = requests.get(_TICKER_URL, params=params, timeout=5)
-            resp.raise_for_status()
-            ticker_data.extend(resp.json())
+            for attempt in range(3):
+                try:
+                    resp = requests.get(_TICKER_URL, params=params, timeout=5)
+                    if resp.status_code == 429:
+                        wait = 2 ** attempt  # 1s → 2s → 4s
+                        logger.warning(f"429 Rate Limit, {wait}s 대기 후 재시도 ({attempt+1}/3)")
+                        time.sleep(wait)
+                        continue
+                    resp.raise_for_status()
+                    ticker_data.extend(resp.json())
+                    break
+                except Exception as e:
+                    if attempt == 2:
+                        raise
+                    time.sleep(1)
 
         # 스테이블코인 제외
         EXCLUDE = {"KRW-USDT", "KRW-USDC", "KRW-DAI", "KRW-BUSD"}