refactor: 重构项目结构

- 将 Python 代码移至 analyzer/ 目录（含 venv）
- 拆分 Go 服务器代码为模块化结构:
  - config/: 配置加载
  - model/: 请求/响应模型
  - service/: 业务逻辑
  - handler/: API处理器
- 添加 .gitignore 文件
- 删除旧的独立脚本文件

analyzer/category.py

@@ -0,0 +1,168 @@
+"""
+交易分类配置和推断逻辑
+
+配置文件: config/category.yaml
+"""
+import yaml
+from pathlib import Path
+
+# =============================================================================
+# 加载 YAML 配置
+# =============================================================================
+
+CONFIG_FILE = Path(__file__).parent / "config" / "category.yaml"
+
+def load_config():
+    """加载分类配置"""
+    with open(CONFIG_FILE, "r", encoding="utf-8") as f:
+        return yaml.safe_load(f)
+
+def reload_config():
+    """重新加载配置（配置文件修改后调用）"""
+    global _config
+    _config = load_config()
+
+# 初始化加载
+_config = load_config()
+
+
+# =============================================================================
+# 配置访问函数
+# =============================================================================
+
+def get_platform_merchants() -> list[str]:
+    """获取需要重新分类的平台型商家列表"""
+    return _config.get("平台商家", [])
+
+
+# =============================================================================
+# 分类推断函数
+# =============================================================================
+
+def infer_category(merchant: str, product: str, income_expense: str) -> tuple[str, bool]:
+    """
+    根据商户名称和商品信息推断交易分类
+    
+    Args:
+        merchant: 交易对方/商户名称
+        product: 商品说明
+        income_expense: 收/支 ("收入" 或 "支出")
+    
+    Returns:
+        (分类名称, 是否确定) - 如果无法确定分类，第二个值为 False
+    """
+    merchant_lower = merchant.lower()
+    product_lower = product.lower()
+    combined = merchant_lower + " " + product_lower
+    
+    # 收入类型处理
+    if income_expense == "收入":
+        for category, keywords in _config["收入分类"].items():
+            for kw in keywords:
+                if kw.lower() in combined:
+                    return category, True
+        return _config["默认分类"]["收入"], False  # 无法确定
+    
+    # 支出类型处理 - 按优先级顺序匹配
+    for category, keywords in _config["支出分类"].items():
+        for kw in keywords:
+            if kw.lower() in combined:
+                return category, True
+    
+    # 转账类特殊处理
+    if "转账" in combined:
+        return _config["默认分类"]["支出"], False  # 转账无法确定具体分类
+    
+    return _config["默认分类"]["支出"], False  # 无法确定
+
+
+def get_all_categories() -> list:
+    """获取所有支出分类列表"""
+    return list(_config["支出分类"].keys()) + [_config["默认分类"]["支出"]]
+
+
+def get_all_income_categories() -> list:
+    """获取所有收入分类列表"""
+    return list(_config["收入分类"].keys())
+
+
+# =============================================================================
+# 分类重推断（用于修正原始分类错误）
+# =============================================================================
+
+def reclassify_if_needed(original_category: str, merchant: str, product: str, 
+                         income_expense: str) -> tuple[str, bool, int]:
+    """
+    检查是否需要重新分类，如果推断出更准确的分类则返回新分类
+    
+    Args:
+        original_category: 原始分类
+        merchant: 交易对方
+        product: 商品说明
+        income_expense: 收/支
+    
+    Returns:
+        (分类名称, 是否已修改, 复核等级)
+        
+        复核等级:
+            0 = 无需复核（分类确定或原分类可信）
+            1 = 低优先级复核（分类被调整，需确认调整是否正确）
+            2 = 高优先级复核（完全无法判断，原分类也是默认分类）
+    """
+    new_category, is_certain = infer_category(merchant, product, income_expense)
+    
+    default_category = _config["默认分类"].get(
+        "支出" if income_expense == "支出" else "收入"
+    )
+    
+    # 判断原分类是否为默认/笼统分类
+    is_original_default = (
+        original_category == default_category or 
+        original_category in ["其他", "其他支出", "其他收入", ""]
+    )
+    
+    # 情况1：推断出具体分类，且与原分类不同 → 调整分类，低优先级复核
+    if new_category != default_category and new_category != original_category:
+        return new_category, True, 1  # 低优先级复核
+    
+    # 情况2：推断失败，但原分类是具体分类 → 信任原分类，无需复核
+    if not is_certain and not is_original_default:
+        return original_category, False, 0  # 信任支付宝原分类
+    
+    # 情况3：推断失败，原分类也是默认分类 → 高优先级复核
+    if not is_certain and is_original_default:
+        return new_category, False, 2  # 高优先级复核
+    
+    # 情况4：分类确定且未调整 → 无需复核
+    return original_category, False, 0
+
+
+# =============================================================================
+# 调试工具
+# =============================================================================
+
+def test_category(merchant: str, product: str = "", income_expense: str = "支出") -> None:
+    """测试分类推断结果"""
+    category, is_certain = infer_category(merchant, product, income_expense)
+    review_level = "无" if is_certain else "高 ⚠️"
+    print(f"商户: {merchant}")
+    print(f"商品: {product}")
+    print(f"收支: {income_expense}")
+    print(f"分类: {category}")
+    print(f"复核: {review_level}")
+    print()
+
+
+if __name__ == "__main__":
+    print("=== 分类测试 ===\n")
+    
+    test_cases = [
+        ("luckin coffee", "订单付款", "支出"),
+        ("美团", "万达影城-美团App", "支出"),
+        ("美团", "茶百道-美团App", "支出"),
+        ("美团", "美宜佳-美团App", "支出"),
+    ]
+    
+    for merchant, product, ie in test_cases:
+        test_category(merchant, product, ie)
+