bsp_monitor: 支持全部20个币对 + 数据源切换至data_provider + Python 3.9兼容

- fetcher.py: 数据源从CCXT改为data_provider HTTP API，新增get_symbols()自动获取所有币对
- main.py: 重构为多币对架构，每个币对独立SymbolState（pivot_monitor/BSP去重/首轮抑制）
- engine.py: format_bsp_detail()支持动态币对名
- ChanPivotMonitor/Classifier: 修复Python 3.9类型注解兼容（X|None → Optional[X]）
- 首轮初始化时不推送中枢和BSP，避免启动时20条消息轰炸

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

bsp_monitor/engine.py

@@ -127,7 +127,7 @@ class ChanEngine:
         cst = dt.astimezone(timezone(timedelta(hours=8)))
         return cst.strftime("%Y-%m-%d %H:%M:%S CST")
 
-    def format_bsp_detail(self, bsp: ChanBSP) -> str:
+    def format_bsp_detail(self, bsp: ChanBSP, symbol: str = "BTC/USDT:USDT") -> str:
         bi = bsp.bi
         klc = bsp.klc
         bsp_type = bsp.type
@@ -136,8 +136,9 @@ class ChanEngine:
         emoji = "🟢" if bsp_dir == Chan_BSP_DIR.BUY else "🔴"
         dir_label = "买点" if bsp_dir == Chan_BSP_DIR.BUY else "卖点"
 
+        symbol_short = symbol.split(":")[0].replace("/", "")
         lines = [
-            f"{emoji} [{dir_label}] {self._bsp_type_name(bsp_type)} — <b>BTC/USDT 1m</b>",
+            f"{emoji} [{dir_label}] {self._bsp_type_name(bsp_type)} — <b>{symbol_short} 1m</b>",
             "",
             f"⏰ 确认: <code>{self._utc_to_cst(klc.end_time)}</code>",
             f"💰 价格: <b>{klc.close:.2f}</b>",