Improve failover controls and preserve manual switching state

.tmp-tests/harbor-startup-recovery-FQjZCa/bin/sing-box

@@ -0,0 +1,11 @@
+#!/usr/bin/env node
+const fs = require('node:fs');
+if (process.argv[2] === 'check') process.exit(0);
+if (process.argv[2] === 'version') {
+  console.log('sing-box version 1.13.18');
+  process.exit(0);
+}
+if (process.argv[2] === 'run') {
+  fs.appendFileSync(process.env.HARBOR_TEST_RUN_MARKER, 'run\n');
+  setInterval(() => {}, 60_000);
+}

.tmp-tests/harbor-startup-recovery-FQjZCa/state.json

@@ -0,0 +1 @@
+{"schemaVersion":6,"revision":4,"profiles":[{"id":"profile-a","label":"Основной","subscriptionUrl":"https://provider.example/0123456789abcdef0123456789abcdef","subscriptionConfig":{"outbounds":[{"type":"vless","tag":"srv_56f1cee6a72c8e7c","server":"boot.example","server_port":443,"uuid":"00000000-0000-4000-8000-000000000000"}]},"servers":[{"id":"srv_56f1cee6a72c8e7c","label":"Boot VPN","host":"boot.example","port":443,"protocol":"vless","tag":"Boot VPN","server":"boot.example","server_port":443,"type":"vless"}],"userInfo":{},"fetchedAt":null,"desiredServerId":"srv_56f1cee6a72c8e7c","lastRefreshAttemptAt":null,"lastRefreshErrorCode":null}],"desiredProfileId":"profile-a","appliedProfileId":"profile-a","appliedServerId":"srv_56f1cee6a72c8e7c","appliedServerSnapshot":{"id":"srv_56f1cee6a72c8e7c","label":"Boot VPN","host":"boot.example","port":443,"protocol":"vless","tag":"Boot VPN","server":"boot.example","server_port":443,"type":"vless"},"routeRules":[{"type":"domain","value":"api.example.com","enabled":true,"outbound":"vpn"},{"type":"domain_suffix","value":"example.com","enabled":true,"outbound":"direct"}],"appliedRouteRules":[],"routeRulesRevision":0,"connectionDesired":"running"}