将调度内核标识从 SimpleLite 全面重命名为 Simple3。

配置段/环境变量、Launcher、健康检查 API、OpenAPI 与前后端文案同步；兼容探测旧 SimpleLite 进程名。

Co-authored-by: Cursor <cursoragent@cursor.com>

MiGu.Server/Fleet/FleetHealthModels.cs

@@ -1,6 +1,6 @@
 namespace MiGu.Server.Fleet;
 
-/// <summary>与 SimpleLite GET /projection/fleet/health 行对齐，供车队运维前端消费。</summary>
+/// <summary>与 Simple3 GET /projection/fleet/health 行对齐，供车队运维前端消费。</summary>
 public sealed class FleetHealthRowDto
 {
     public int CarId { get; set; }