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/README.md

@@ -0,0 +1,87 @@
+<p align="center">
+  <a href="https://github.com/lucide-icons/lucide">
+    <img src="https://lucide.dev/package-logos/lucide-react.svg" alt="Lucide icon library for React applications." width="540">
+  </a>
+</p>
+
+<p align="center">
+Lucide icon library for React applications.
+</p>
+
+<div align="center">
+
+  [![npm](https://img.shields.io/npm/v/lucide-react?color=blue)](https://www.npmjs.com/package/lucide-react)
+  ![NPM Downloads](https://img.shields.io/npm/dw/lucide-react)
+  [![License](https://img.shields.io/badge/license-ISC-green)](https://lucide.dev/license)
+</div>
+
+<p align="center">
+  <a href="https://lucide.dev/guide/">About</a>
+  ·
+  <a href="https://lucide.dev/icons/">Icons</a>
+  ·
+  <a href="https://lucide.dev/guide/react">Documentation</a>
+  ·
+  <a href="https://lucide.dev/license">License</a>
+</p>
+
+# Lucide React
+
+Implementation of the Lucide icon library for React applications.
+
+## Installation
+
+```sh
+pnpm add lucide-react
+```
+
+```sh
+npm install lucide-react
+```
+
+```sh
+yarn add lucide-react
+```
+
+```sh
+bun add lucide-react
+```
+
+## Documentation
+
+For full documentation, visit [lucide.dev](https://lucide.dev/guide/packages/lucide-react)
+
+## Community
+
+Join the [Discord server](https://discord.gg/EH6nSts) to chat with the maintainers and other users.
+
+## License
+
+Lucide is licensed under the ISC license. See [LICENSE](https://lucide.dev/license).
+
+[//]: <> (Sponsors)
+
+## Sponsors
+
+<a href="https://vercel.com?utm_source=lucide&utm_campaign=oss">
+  <img src="https://lucide.dev/vercel.svg" alt="Powered by Vercel" width="200" />
+</a>
+
+<a href="https://www.digitalocean.com/?refcode=b0877a2caebd&utm_campaign=Referral_Invite&utm_medium=Referral_Program&utm_source=badge"><img src="https://lucide.dev/digitalocean.svg" width="200" alt="DigitalOcean Referral Badge" /></a>
+
+### Hero backers 🦸
+
+<a href="https://zephyr-cloud.io/"><img src="https://lucide.dev/sponsors/zephyr-cloud.svg" width="180" alt="Zephyr Cloud – From idea to prod: fast micro-frontend delivery!" /></a>
+
+### Awesome backers 🍺
+
+<a href="https://github.com/pdfme/pdfme"><img src="https://lucide.dev/sponsors/pdfme.svg" width="180" alt="pdfme – Open-source PDF generation library built with TypeScript and React." /></a>
+<a href="https://www.paxhistoria.co/"><img src="https://lucide.dev/sponsors/paxhistoria.svg?" width="180" alt="Pax Historia – An alternate history sandbox game" /></a>
+
+### Backers ☕
+
+<a href="https://www.fina.money/"><img src="https://lucide.dev/sponsors/fina-money.png" width="180" alt="Fina Money – Modular Finance Tracker" /></a>
+
+### Other contributors 💸
+
+You can find all our past and non-recurring financial contributors at [our Open Collective page](https://opencollective.com/lucide-icons).