chore(config): 添加环境变量示例及.gitignore更新

- 新增 .env.example，包含 Tushare API、钉钉机器人和PostgreSQL数据库配置模板
- 更新.gitignore，忽略本地配置文件如 .env.local 和 config_local.py
- 添加对报表文件命名规则的支持，保留示例文件不忽略
- 删除废弃的 chart.py 及相关图表模块代码
- 新增 config/settings.py，实现从环境变量读取配置的统一接口
- 设置数据目录及缓存目录，确保目录存在，提高配置管理规范性

core/common/db.py

@@ -0,0 +1,96 @@
+"""
+数据库配置和连接工具
+"""
+
+import psycopg2
+from psycopg2.extras import RealDictCursor
+from sqlalchemy import create_engine
+import pandas as pd
+from loguru import logger
+from typing import Optional
+
+from config.settings import get_db_config
+
+
+class DatabaseManager:
+    """数据库管理类"""
+
+    def __init__(self, config: dict = None):
+        self.config = config or get_db_config()
+        self.engine = None
+
+    def get_engine(self):
+        """获取SQLAlchemy引擎"""
+        if self.engine is None:
+            conn_str = (
+                f"postgresql://{self.config['username']}:{self.config['password']}"
+                f"@{self.config['host']}:{self.config['port']}/{self.config['database']}"
+            )
+            self.engine = create_engine(
+                conn_str,
+                pool_pre_ping=True,
+                pool_recycle=300,
+                echo=False,
+            )
+        return self.engine
+
+    def get_connection(self):
+        """获取psycopg2连接"""
+        return psycopg2.connect(
+            host=self.config["host"],
+            port=self.config["port"],
+            database=self.config["database"],
+            user=self.config["username"],
+            password=self.config["password"],
+        )
+
+    def test_connection(self) -> bool:
+        """测试数据库连接"""
+        try:
+            with self.get_connection() as conn:
+                with conn.cursor() as cursor:
+                    cursor.execute("SELECT 1")
+                    result = cursor.fetchone()
+                    logger.info("数据库连接测试成功")
+                    return True
+        except Exception as e:
+            logger.error(f"数据库连接测试失败: {e}")
+            return False
+
+    def execute_query(self, query: str, params: tuple = None) -> Optional[list]:
+        """执行查询并返回结果"""
+        try:
+            with self.get_connection() as conn:
+                with conn.cursor(cursor_factory=RealDictCursor) as cursor:
+                    cursor.execute(query, params)
+                    result = cursor.fetchall()
+                    return [dict(row) for row in result]
+        except Exception as e:
+            logger.error(f"执行查询失败: {e}")
+            return None
+
+    def insert_dataframe(
+        self, df: pd.DataFrame, table_name: str, if_exists: str = "append"
+    ) -> bool:
+        """将DataFrame插入到数据库表"""
+        try:
+            engine = self.get_engine()
+            df.to_sql(
+                table_name,
+                engine,
+                if_exists=if_exists,
+                index=False,
+                method="multi",
+                chunksize=1000,
+            )
+            logger.info(f"成功插入 {len(df)} 条记录到表 {table_name}")
+            return True
+        except Exception as e:
+            logger.error(f"插入数据到表 {table_name} 失败: {e}")
+            return False
+
+    def close(self):
+        """关闭连接"""
+        if self.engine:
+            self.engine.dispose()
+            self.engine = None