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-logical-assignment-operators/lib/index.js

@@ -0,0 +1,55 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var _helperPluginUtils = require("@babel/helper-plugin-utils");
+var _core = require("@babel/core");
+var _default = exports.default = (0, _helperPluginUtils.declare)(api => {
+  api.assertVersion("^7.0.0-0 || ^8.0.0-0 || >8.0.0-alpha <8.0.0-beta");
+  return {
+    name: "transform-logical-assignment-operators",
+    manipulateOptions: (_, parser) => parser.plugins.push("logicalAssignment"),
+    visitor: {
+      AssignmentExpression(path) {
+        const {
+          node,
+          scope
+        } = path;
+        const {
+          operator,
+          left,
+          right
+        } = node;
+        const operatorTrunc = operator.slice(0, -1);
+        if (!_core.types.LOGICAL_OPERATORS.includes(operatorTrunc)) {
+          return;
+        }
+        const lhs = _core.types.cloneNode(left);
+        if (_core.types.isMemberExpression(left)) {
+          const {
+            object,
+            property,
+            computed
+          } = left;
+          const memo = scope.maybeGenerateMemoised(object);
+          if (memo) {
+            left.object = memo;
+            lhs.object = _core.types.assignmentExpression("=", _core.types.cloneNode(memo), object);
+          }
+          if (computed) {
+            const memo = scope.maybeGenerateMemoised(property);
+            if (memo) {
+              left.property = memo;
+              lhs.property = _core.types.assignmentExpression("=", _core.types.cloneNode(memo), property);
+            }
+          }
+        }
+        path.replaceWith(_core.types.logicalExpression(operatorTrunc, lhs, _core.types.assignmentExpression("=", left, right)));
+      }
+    }
+  };
+});
+
+//# sourceMappingURL=index.js.map