Add default USD-M perpetual BTC/ETH/BNB and fix futures WS stream

Seed um BTCUSDT/ETHUSDT/BNBUSDT as default symbols. The legacy futures
route fstream.binance.com/stream accepts connections but no longer pushes
data, so switch to /market/stream. Receive with a timeout so symbol
changes are picked up and silent connections are reconnected.

backend/alembic/versions/20261013_bf0ffbfcaf9a_default_um_symbols.py

@@ -0,0 +1,35 @@
+"""default um symbols
+
+Revision ID: bf0ffbfcaf9a
+Revises: c7e1beb72c75
+Create Date: 2026-10-13 06:01:27.204671
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'bf0ffbfcaf9a'
+down_revision: Union[str, Sequence[str], None] = 'c7e1beb72c75'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # U 本位永续的默认交易对；精度取自 2026-10-13 币安 fapi exchangeInfo（tickSize 0.10/0.01/0.010，stepSize 0.001/0.001/0.01）
+    op.execute(sa.text("""
+        INSERT INTO market_symbols (market, symbol, base, quote, price_precision, volume_precision, status, is_default)
+        VALUES ('um', 'BTCUSDT', 'BTC', 'USDT', 1, 3, 'pending', true),
+               ('um', 'ETHUSDT', 'ETH', 'USDT', 2, 3, 'pending', true),
+               ('um', 'BNBUSDT', 'BNB', 'USDT', 2, 2, 'pending', true)
+        ON CONFLICT (market, symbol) DO UPDATE SET is_default = true
+    """))
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    op.execute(sa.text("UPDATE market_symbols SET is_default = false WHERE market = 'um' AND symbol IN ('BTCUSDT', 'ETHUSDT', 'BNBUSDT')"))

backend/src/alphapulse/market/binance.py

@@ -15,7 +15,8 @@ REST = {
     "um": {"base": "https://fapi.binance.com", "klines": "/fapi/v1/klines", "exchange_info": "/fapi/v1/exchangeInfo",
            "ticker": "/fapi/v1/ticker/24hr", "weight_limit": 2400, "kline_limit": 1500},
 }
-WS = {"spot": "wss://stream.binance.com:9443/stream", "um": "wss://fstream.binance.com/stream"}
+# 合约旧路由 fstream.binance.com/stream 能连上但不推送数据，K 线/行情流在 /market 路由下
+WS = {"spot": "wss://stream.binance.com:9443/stream", "um": "wss://fstream.binance.com/market/stream"}
 
 # 权重用量超过上限的这个比例就等到下一分钟
 WEIGHT_RATIO = 0.5

backend/src/alphapulse/market/worker.py

@@ -26,6 +26,8 @@ logger = logging.getLogger("alphapulse.market.worker")
 PAGES_PER_TURN = 20
 CATCHUP_SECONDS = 3600
 SYMBOL_CHECK_SECONDS = 10
+# miniTicker 约每秒推送，这么久没消息视为连接卡死
+STALL_SECONDS = 60
 ACTIVE_STATUSES = ("pending", "backfilling", "ready")
 
 client = BinanceClient()
@@ -209,8 +211,19 @@ async def stream_loop(market: str) -> None:
                 logger.info("%s WS 已连接：%d 个交易对，%d 个流", market, len(symbols), len(streams))
                 catchup_needed.set()
                 next_check = time.monotonic() + SYMBOL_CHECK_SECONDS
-                async for raw in ws:
+                last_message = time.monotonic()
+                while True:
+                    # 带超时接收：没有消息时也要按时检查交易对变化和连接是否卡死
+                    try:
+                        raw = await asyncio.wait_for(ws.recv(), timeout=SYMBOL_CHECK_SECONDS)
+                    except TimeoutError:
+                        pass
+                    else:
+                        last_message = time.monotonic()
                         await handle_message(market, raw)
+                    if time.monotonic() - last_message >= STALL_SECONDS:
+                        logger.warning("%s WS %ds 未收到消息，重连", market, STALL_SECONDS)
+                        break
                     if time.monotonic() >= next_check:
                         next_check = time.monotonic() + SYMBOL_CHECK_SECONDS
                         if await active_symbols(market) != symbols: