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/@babel/plugin-transform-regenerator/lib/index.js

@@ -0,0 +1,41 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var _helperPluginUtils = require("@babel/helper-plugin-utils");
+var _visit = require("./regenerator/visit.js");
+var _default = exports.default = (0, _helperPluginUtils.declare)(({
+  types: t,
+  traverse,
+  assertVersion
+}) => {
+  assertVersion(7);
+  return {
+    name: "transform-regenerator",
+    visitor: traverse.visitors.merge([(0, _visit.getVisitor)(), {
+      CallExpression(path) {
+        var _this$availableHelper;
+        if (!((_this$availableHelper = this.availableHelper) != null && _this$availableHelper.call(this, "regeneratorRuntime"))) {
+          return;
+        }
+        const callee = path.get("callee");
+        if (!callee.isMemberExpression()) return;
+        const obj = callee.get("object");
+        if (obj.isIdentifier({
+          name: "regeneratorRuntime"
+        })) {
+          const helper = this.addHelper("regeneratorRuntime");
+          if (t.isArrowFunctionExpression(helper)) {
+            obj.replaceWith(helper.body);
+            return;
+          }
+          obj.replaceWith(t.callExpression(helper, []));
+        }
+      }
+    }])
+  };
+});
+
+//# sourceMappingURL=index.js.map