audit(csv): drop user_id and target_id columns

internal/server/http/ui_audit.go

@@ -172,22 +172,23 @@ func (s *Server) handleUIAuditCSV(w stdhttp.ResponseWriter, r *stdhttp.Request)
 
 	cw := csv.NewWriter(w)
 	defer cw.Flush()
-	_ = cw.Write([]string{"timestamp_utc", "actor", "user", "user_id", "action", "target_kind", "target_id", "target_name", "payload"})
+	// user_id and target_id are internal ULIDs that carry no meaning
+	// to anyone reading the CSV — the resolved name (or — for system
+	// rows / non-host targets) is what an operator wants. The HTML
+	// page still shows IDs in the Target column for traceability when
+	// no name is available; the CSV is for human reporting only.
+	_ = cw.Write([]string{"timestamp_utc", "actor", "user", "action", "target_kind", "target_name", "payload"})
 	for _, e := range entries {
-		var uid, uname string
+		var uname string
 		if e.UserID != nil {
-			uid = *e.UserID
-			uname = userNames[uid]
+			uname = userNames[*e.UserID]
 		}
-		var tk, tid, tname string
+		var tk, tname string
 		if e.TargetKind != nil {
 			tk = *e.TargetKind
 		}
-		if e.TargetID != nil {
-			tid = *e.TargetID
-		}
-		if tk == "host" {
-			tname = hostNames[tid]
+		if tk == "host" && e.TargetID != nil {
+			tname = hostNames[*e.TargetID]
 		}
 		payload := ""
 		if len(e.Payload) > 0 {
@@ -195,8 +196,7 @@ func (s *Server) handleUIAuditCSV(w stdhttp.ResponseWriter, r *stdhttp.Request)
 		}
 		_ = cw.Write([]string{
 			e.TS.UTC().Format("2006-01-02 15:04:05"),
-			e.Actor, uname, uid, e.Action,
-			tk, tid, tname, payload,
+			e.Actor, uname, e.Action, tk, tname, payload,
 		})
 	}
 }