Add audit logs.

API/ROLAC.API/Services/Logging/IAuditLogger.cs

@@ -0,0 +1,29 @@
+using ROLAC.API.Entities.Logging;
+
+namespace ROLAC.API.Services.Logging;
+
+/// <summary>
+/// Records audit events that don't flow through EF change tracking — security actions
+/// (login/logout/role changes) and key business actions (check issued, expense approved, ...).
+/// Data-change audits are produced automatically by <c>AuditLogInterceptor</c>; use this for the
+/// semantic action + human summary the raw diff can't express.
+/// </summary>
+public interface IAuditLogger
+{
+    /// <summary>
+    /// Build and enqueue an audit row. <paramref name="before"/>/<paramref name="after"/> are
+    /// serialized into the <c>Changes</c> JSON. Never throws — failures are dropped like all logs.
+    /// </summary>
+    void Write(
+        string action,
+        string category,
+        LogLevelEnum level = LogLevelEnum.Information,
+        string? entityName = null,
+        string? entityId = null,
+        string? summary = null,
+        object? before = null,
+        object? after = null,
+        string? userId = null,
+        string? userEmail = null,
+        string? ipAddress = null);
+}