feat(audit): ScadaBridge IAuditActorAccessor + wire audit Actor from Auth principal at authenticated emit sites (Phase 3)

src/ZB.MOM.WW.ScadaBridge.Security/ServiceCollectionExtensions.cs

@@ -4,6 +4,7 @@ using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using ZB.MOM.WW.Auth.Abstractions.Roles;
 using ZB.MOM.WW.Auth.AspNetCore;
+using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Services;
 
 namespace ZB.MOM.WW.ScadaBridge.Security;
 
@@ -49,6 +50,18 @@ public static class ServiceCollectionExtensions
         services.AddScoped<JwtTokenService>();
         services.AddScoped<RoleMapper>();
 
+        // Audit Actor wiring (Phase 3): the user-facing inbound API audit path
+        // sources AuditEvent.Actor from the authenticated principal via this
+        // seam. HttpAuditActorAccessor reads IHttpContextAccessor.HttpContext?.User
+        // (canonical username claim, Identity.Name fallback) and returns null when
+        // there is no authenticated interactive user — so the caller keeps its
+        // existing actor/fallback (API-key name, "system"). Registered as a
+        // singleton (it is stateless and only dereferences the ambient request);
+        // AddHttpContextAccessor is idempotent (TryAdd-based) so calling it here
+        // is safe even though the Host's AddCentralUI also registers it.
+        services.AddHttpContextAccessor();
+        services.AddSingleton<IAuditActorAccessor, HttpAuditActorAccessor>();
+
         // Auth-adoption Task 1.1: register the shared IGroupRoleMapper<string>
         // seam additively, wrapping RoleMapper to reuse its DB-backed mapping +
         // site-scope union semantics. Scoped to match RoleMapper's lifetime (it