Add sync error logging, extend error flash, fix unload saves

- Log workforce sync errors to backend stdout so they appear in docker logs
- Extend error flash from 5s to 15s so errors are readable
- Replace sendBeacon (POST-only) with keepalive fetch (PUT) on unload —
  sendBeacon was hitting 404s on all three unload saves

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/node_modules/rollup/dist/parseAst.js

@@ -0,0 +1,22 @@
+/*
+  @license
+	Rollup.js v4.62.2
+	Fri, 19 Jun 2026 14:55:11 GMT - commit 8faa18777374582bb813d54ce3623f4acf1f9e0b
+
+	https://github.com/rollup/rollup
+
+	Released under the MIT License.
+*/
+'use strict';
+
+Object.defineProperty(exports, Symbol.toStringTag, { value: 'Module' });
+
+require('./native.js');
+const parseAst_js = require('./shared/parseAst.js');
+require('node:path');
+
+
+
+exports.parseAst = parseAst_js.parseAst;
+exports.parseAstAsync = parseAst_js.parseAstAsync;
+//# sourceMappingURL=parseAst.js.map