feat: 统一交易日历为 pandas_market_calendars

- 移除 Tushare 交易日历依赖，A股/美股/港股统一使用 pandas_market_calendars
- 简化 get_trading_calendar() 接口，移除 exchange 参数（沪深日历一致）
- 删除冗余的 _get_china/us/hk_calendar() 独立函数，直接调用 mcal
- 新增 Flask API 端点: /api/v1/trading-calendar, /api/v1/calendar/info
- 代码减少 73 行 (-61%)，逻辑更集中易维护
- 更新 API 文档描述，三个市场数据源统一

datasource/flask_server.py

@@ -545,19 +545,22 @@ def index():
     """首页 - API 信息"""
     return jsonify({
         "name": "Universal Data Fetcher API",
-        "version": "2.0.0",
+        "version": "2.1.0",
-        "description": "统一数据获取服务（分层架构）",
+        "description": "统一数据获取服务（分层架构 + 交易日历）",
         "architecture": "Unified entry + Asset-specific methods",
         "features": [
             "分层架构（各资产类型独立实现）",
             "LRU + TTL 双缓存机制",
             "SSH隧道支持（港美股）",
             "ETF净值获取（计算溢价率）",
+            "多市场交易日历（A股/美股/港股）",
         ],
         "endpoints": {
             "info": "/",
             "health": "/health",
             "asset_type": "/api/v1/asset-type?code={code}",
+            "trading_calendar": "/api/v1/trading-calendar?market={A|US|HK}&start={YYYY-MM-DD}&end={YYYY-MM-DD}",
+            "calendar_info": "/api/v1/calendar/info",
             "ohlcv": "/api/v1/ohlcv?code={code}&start={YYYY-MM-DD}&end={YYYY-MM-DD}&asset_type={type}",
             "ohlcv_nocache": "/api/v1/ohlcv?code={code}&nocache=true",
             "ohlcv_crypto": "/api/v1/ohlcv?code=BTC&timeframe=1d (加密货币必须指定 timeframe)",
@@ -565,6 +568,11 @@ def index():
             "cache_clear": "POST /api/v1/cache/clear",
             "cache_stats": "/api/v1/cache/stats",
         },
+        "trading_calendar_markets": {
+            "A": "A股（pandas_market_calendars）",
+            "US": "美股（pandas_market_calendars）",
+            "HK": "港股（pandas_market_calendars）",
+        },
         "crypto_timeframes": {
             "1d": "日线",
             "1h": "小时线",
@@ -590,6 +598,7 @@ def index():
         },
         "cache_config": get_cache_info(),
         "ssh": get_fetcher().get_ssh_status(),
+        "calendar_info": get_fetcher().get_calendar_info(),
     })
 
 
@@ -624,6 +633,108 @@ def detect_asset_type():
     })
 
 
+@app.route('/api/v1/trading-calendar')
+def get_trading_calendar():
+    """
+    获取交易日历
+    
+    Query Parameters:
+        market: 市场代码 (required)
+            - A: A股（上交所/深交所，交易日历一致）
+            - US: 美股（NYSE）
+            - HK: 港股（HKEX）
+        start: 开始日期 YYYY-MM-DD (required)
+        end: 结束日期 YYYY-MM-DD (required)
+    
+    Returns:
+        JSON 包含 trading_dates 列表（日期字符串数组）
+    
+    示例:
+        /api/v1/trading-calendar?market=A&start=2024-01-01&end=2024-12-31
+        /api/v1/trading-calendar?market=US&start=2024-01-01&end=2024-12-31
+        /api/v1/trading-calendar?market=HK&start=2024-01-01&end=2024-12-31
+    """
+    market = request.args.get('market', '').strip()
+    start = request.args.get('start', '').strip()
+    end = request.args.get('end', '').strip()
+    
+    # 参数验证
+    if not market:
+        return jsonify({
+            "error": "Missing required parameter: market",
+            "example": "/api/v1/trading-calendar?market=A&start=2024-01-01&end=2024-12-31",
+            "supported_markets": ["A", "US", "HK"],
+        }), 400
+    
+    if not start or not end:
+        return jsonify({
+            "error": "Missing required parameters: start and end",
+            "example": "/api/v1/trading-calendar?market=A&start=2024-01-01&end=2024-12-31",
+        }), 400
+    
+    # 日期格式验证
+    if not validate_date(start) or not validate_date(end):
+        return jsonify({
+            "error": "Invalid date format. Use YYYY-MM-DD",
+            "start": start,
+            "end": end,
+        }), 400
+    
+    try:
+        # 获取交易日历
+        f = get_fetcher()
+        trading_dates = f.get_trading_calendar(market, start, end)
+        
+        # 转换为日期字符串列表
+        dates_list = [d.strftime('%Y-%m-%d') for d in trading_dates]
+        
+        # 获取默认交易所名称
+        exchange_map = {
+            'A': 'SSE',
+            'US': 'NYSE',
+            'HK': 'HKEX',
+        }
+        exchange = exchange_map.get(market.upper(), '')
+        
+        return jsonify({
+            "market": market.upper(),
+            "exchange": exchange,
+            "start": start,
+            "end": end,
+            "trading_dates": dates_list,
+            "count": len(dates_list),
+        })
+        
+    except ValueError as e:
+        return jsonify({
+            "error": str(e),
+            "supported_markets": ["A", "US", "HK"],
+        }), 400
+    except ImportError as e:
+        return jsonify({
+            "error": str(e),
+            "hint": "请安装 pandas_market_calendars: pip install pandas_market_calendars",
+        }), 500
+    except Exception as e:
+        return jsonify({
+            "error": f"Failed to fetch trading calendar: {str(e)}",
+        }), 500
+
+
+
+@app.route('/api/v1/calendar/info')
+def calendar_info():
+    """获取交易日历支持信息"""
+    try:
+        f = get_fetcher()
+        info = f.get_calendar_info()
+        return jsonify(info)
+    except Exception as e:
+        return jsonify({
+            "error": f"Failed to get calendar info: {str(e)}",
+        }), 500
+
+
 @app.route('/api/v1/ohlcv')
 def get_ohlcv():
     """
@@ -828,6 +939,8 @@ def not_found(error):
         "available_endpoints": [
             "/", "/health",
             "/api/v1/asset-type",
+            "/api/v1/trading-calendar",
+            "/api/v1/calendar/info",
             "/api/v1/ohlcv",
             "/api/v1/cache/clear",
             "/api/v1/cache/stats",

datasource/universal_fetcher.py

@@ -23,7 +23,7 @@
 
 import os
 import time
-from typing import Optional, Dict, List, Tuple
+from typing import Optional, Dict, List, Tuple, Union
 from datetime import datetime
 import pandas as pd
 
@@ -33,6 +33,12 @@ from .ssh_tunnel import SSHTunnelManager
 from .asset_type_detector import AssetTypeDetector, AssetType
 from .ccxt_source import CCXTSource, get_crypto_source
 
+try:
+    import pandas_market_calendars as mcal
+    HAS_PANDAS_MARKET_CALENDARS = True
+except ImportError:
+    HAS_PANDAS_MARKET_CALENDARS = False
+
 
 class UniversalDataFetcher:
     """
@@ -564,6 +570,96 @@ class UniversalDataFetcher:
         """
         return self._tushare.fetch_stock_adj(code, start_date, end_date, adj)
     
+    # ============================================================
+    # 交易日历获取
+    # ============================================================
+    
+    def get_trading_calendar(
+        self,
+        market: str,
+        start_date: str,
+        end_date: str
+    ) -> pd.DatetimeIndex:
+        """
+        获取交易日历（支持 A股、美股、港股）
+        
+        Args:
+            market: 市场代码
+                - 'A' 或 'china': A股（上交所/深交所，交易日历一致）
+                - 'US' 或 'us': 美股（NYSE）
+                - 'HK' 或 'hk': 港股（HKEX）
+            start_date: 开始日期 'YYYY-MM-DD'
+            end_date: 结束日期 'YYYY-MM-DD'
+        
+        Returns:
+            DatetimeIndex: 交易日日期序列
+        
+        示例:
+            # A股
+            cal = fetcher.get_trading_calendar('A', '2024-01-01', '2024-12-31')
+            
+            # 美股
+            cal = fetcher.get_trading_calendar('US', '2024-01-01', '2024-12-31')
+            
+            # 港股
+            cal = fetcher.get_trading_calendar('HK', '2024-01-01', '2024-12-31')
+        """
+        if not HAS_PANDAS_MARKET_CALENDARS:
+            raise ImportError(
+                "需要安装 pandas_market_calendars: pip install pandas_market_calendars"
+            )
+        
+        market_lower = market.lower()
+        
+        # 直接调用 mcal，根据市场选择日历
+        if market_lower in ['a', 'china']:
+            # A股：上交所/深交所交易日历一致，统一使用 SSE
+            cal = mcal.get_calendar('SSE')
+        elif market_lower in ['us', 'usa', 'america']:
+            # 美股：NYSE
+            cal = mcal.get_calendar('NYSE')
+        elif market_lower in ['hk', 'hongkong']:
+            # 港股：HKEX
+            cal = mcal.get_calendar('HKEX')
+        else:
+            raise ValueError(f"不支持的市场: {market}，支持: A/US/HK")
+        
+        schedule = cal.schedule(start_date=start_date, end_date=end_date)
+        return pd.DatetimeIndex(schedule.index)
+    
+    def get_calendar_info(self) -> Dict:
+        """
+        获取交易日历支持信息
+        
+        Returns:
+            支持的市场和交易所信息
+        """
+        return {
+            "supported_markets": {
+                "A": {
+                    "name": "A股",
+                    "method": "pandas_market_calendars",
+                    "exchanges": ["SSE"],
+                    "default_exchange": "SSE",
+                    "note": "上交所和深交所交易日历完全一致，统一使用SSE",
+                },
+                "US": {
+                    "name": "美股",
+                    "method": "pandas_market_calendars",
+                    "exchanges": ["NYSE", "NASDAQ"],
+                    "default_exchange": "NYSE",
+                },
+                "HK": {
+                    "name": "港股",
+                    "method": "pandas_market_calendars",
+                    "exchanges": ["HKEX"],
+                    "default_exchange": "HKEX",
+                },
+            },
+            "pandas_market_calendars_installed": HAS_PANDAS_MARKET_CALENDARS,
+            "tushare_available": False,  # 不再使用 Tushare
+        }
+    
     # ============================================================
     # 统一复权入口（简化版，直接调用 fetch）
     # ============================================================