shared: add independent IPv4 and IPv6 collection [CI]

backend/shared/MoShiro.Protocol/IpVersions.cs

@@ -0,0 +1,13 @@
+namespace MoShiro.Protocol;
+
+/// <summary>测量路径的地址族。旧契约缺省为 IPv4；IPv6 使用独立的线路和序列。</summary>
+public static class IpVersions
+{
+    public const string V4 = "ipv4";
+    public const string V6 = "ipv6";
+
+    public static bool IsValid(string? value) => value is V4 or V6;
+
+    public static string LineSeries(string probeId, string ipVersion) =>
+        RawChunkHeader.LinePrefix + probeId + (ipVersion == V6 ? ":ipv6" : "");
+}