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/Configs/TrafficRule.cs

@@ -0,0 +1,16 @@
+namespace MiGu.Server.Configs;
+
+public record IntersectionPolicy(string Id, List<string> SiteIds, string Mode);
+public record ZoneMutex(string Id, List<string> ZoneIds);
+public record DynamicYield(string Id, string From, string To, string Condition);
+
+public record TrafficRule(
+    List<IntersectionPolicy> Intersections,
+    List<ZoneMutex> Mutex,
+    List<DynamicYield> Yields)
+{
+    public static TrafficRule Default() => new(
+        Intersections: new List<IntersectionPolicy> { new("IX1", new List<string> { "S006", "S007" }, "mutex") },
+        Mutex: new List<ZoneMutex> { new("MZ1", new List<string> { "Z-CROSS" }) },
+        Yields: new List<DynamicYield> { new("YD1", "A 区", "B 区", "priority<peer") });
+}