R-621: the hold panel points at the log the hold kept

A held app's page now says, inside the hold panel, that the app's own log from
before it was stopped was kept, with a Napló link to the logs page that serves
it (0b93e1a). Shown only for an update hold with a non-empty kept log
(Manager.HoldLogKept). New copy through the bundle (hu + en), parity case
app_info_hold_log captured when born.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/web/handlers.go

@@ -896,6 +896,13 @@ func (s *Server) appDetailHandler(w http.ResponseWriter, r *http.Request, slug s
 		data["AutoUpdateLine"] = s.msg(r, "app_info.auto_update_done", undoneWhen(found.AppConfig.LastAutoUpdate.At))
 	}
 
+	// R-621: a held app's own log, kept by the hold before its containers were removed, is reachable
+	// from the hold panel — the panel says it was kept and links the logs page that serves it. Only
+	// for an update hold (an unhealthy stop keeps no log), and only when a non-empty log exists.
+	if found.Deployed && found.HoldReason != "" && found.HoldKind != "unhealthy_stop" && s.stackMgr != nil {
+		data["HoldLogKept"] = s.stackMgr.HoldLogKept(found.Name)
+	}
+
 	s.executeTemplate(w, r, "app_info", data)
 }