Restructure solution layout by module

src/Signals/StellaOps.Signals/Routing/SignalsPolicies.cs

@@ -0,0 +1,22 @@
+namespace StellaOps.Signals.Routing;
+
+/// <summary>
+/// Signals service authorization policy names and scope constants.
+/// </summary>
+public static class SignalsPolicies
+{
+    /// <summary>
+    /// Scope required for read operations.
+    /// </summary>
+    public const string Read = "signals:read";
+
+    /// <summary>
+    /// Scope required for write operations.
+    /// </summary>
+    public const string Write = "signals:write";
+
+    /// <summary>
+    /// Scope required for administrative operations.
+    /// </summary>
+    public const string Admin = "signals:admin";
+}