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/lucide-react/dist/esm/icons/tv-minimal-play.mjs

@@ -0,0 +1,24 @@
+/**
+ * @license lucide-react v1.24.0 - ISC
+ *
+ * This source code is licensed under the ISC license.
+ * See the LICENSE file in the root directory of this source tree.
+ */
+
+import createLucideIcon from '../createLucideIcon.mjs';
+
+const __iconNode = [
+  [
+    "path",
+    {
+      d: "M15.033 9.44a.647.647 0 0 1 0 1.12l-4.065 2.352a.645.645 0 0 1-.968-.56V7.648a.645.645 0 0 1 .967-.56z",
+      key: "vbtd3f"
+    }
+  ],
+  ["path", { d: "M7 21h10", key: "1b0cd5" }],
+  ["rect", { width: "20", height: "14", x: "2", y: "3", rx: "2", key: "48i651" }]
+];
+const TvMinimalPlay = createLucideIcon("tv-minimal-play", __iconNode);
+
+export { __iconNode, TvMinimalPlay as default };
+//# sourceMappingURL=tv-minimal-play.mjs.map