config: use direct MySQL connection string

Evergreen.Health.Api/Configuration/Database.local.example.json

@@ -1,10 +0,0 @@
-{
-  "DbConnection": {
-    "ConnectionConfigs": [
-      {
-        "DbType": "MySqlConnector",
-        "ConnectionString": "Server=127.0.0.1;Port=3306;Database=evergreen_health;User ID=root;Password=CHANGE_ME;CharSet=utf8mb4;SslMode=None;Pooling=true;Connection Timeout=30"
-      }
-    ]
-  }
-}

Evergreen.Health.Api/Program.cs

@@ -10,12 +10,6 @@ public class WebComponent : IWebComponent
 {
     public void Load(WebApplicationBuilder builder, ComponentContext componentContext)
     {
-        // 本机数据库配置。该文件已加入 .gitignore，仅用于保存真实连接信息。
-        builder.Configuration.AddJsonFile(
-            "Configuration/Database.local.json",
-            optional: true,
-            reloadOnChange: true);
-
         // 设置日志过滤
         builder.Logging.AddFilter((provider, category, logLevel) =>
         {