feat: 迁入 MiGu.Server、平台前端与车辆列表 reflection 回退

从 Simple-FR 拆出 Platform.Server 并重命名为 MiGu.Server；frontends 源码与构建脚本迁入本仓库。地图监控在 projection/cars 失败或为空时回退 reflection 车辆列表；Simple 仓库已移除旧 Platform.Server。

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

MiGu.Server/Properties/launchSettings.json

@@ -0,0 +1,14 @@
+{
+  "$schema": "https://json.schemastore.org/launchsettings.json",
+  "profiles": {
+    "MiGu.Server": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": false,
+      "applicationUrl": "http://0.0.0.0:8080",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}