refactor(battle-node): WireConstants for SIO event names + crypto RNG battle id

SVSim.BattleNode/Protocol/WireConstants.cs

@@ -0,0 +1,27 @@
+namespace SVSim.BattleNode.Protocol;
+
+/// <summary>
+/// String constants that show up on the wire as opaque tags. Lifting them out of
+/// inline string literals gives each one a single source of truth and a name that
+/// reads at the use site.
+/// </summary>
+internal static class WireConstants
+{
+    /// <summary>SIO event name for ordered server-pushed frames (the lifecycle channel).</summary>
+    public const string SynchronizeEvent = "synchronize";
+
+    /// <summary>SIO event name for client-emitted msg frames + their ack-responses.</summary>
+    public const string MsgEvent = "msg";
+
+    /// <summary>SIO event name for Gungnir keepalive frames (both directions).</summary>
+    public const string AliveEvent = "alive";
+
+    /// <summary>
+    /// Placeholder UUID we stamp on every server-originated envelope. Prod servers stamp a
+    /// real per-request UUID; the client doesn't validate it.
+    /// </summary>
+    public const string ServerUuid = "node-stub";
+
+    /// <summary>Gungnir scs/ocs value the v1 server reports unconditionally.</summary>
+    public const string OnlineStatus = "ONLINE";
+}