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/glob/dist/esm/has-magic.d.ts

@@ -0,0 +1,14 @@
+import { GlobOptions } from './glob.js';
+/**
+ * Return true if the patterns provided contain any magic glob characters,
+ * given the options provided.
+ *
+ * Brace expansion is not considered "magic" unless the `magicalBraces` option
+ * is set, as brace expansion just turns one string into an array of strings.
+ * So a pattern like `'x{a,b}y'` would return `false`, because `'xay'` and
+ * `'xby'` both do not contain any magic glob characters, and it's treated the
+ * same as if you had called it on `['xay', 'xby']`. When `magicalBraces:true`
+ * is in the options, brace expansion _is_ treated as a pattern having magic.
+ */
+export declare const hasMagic: (pattern: string | string[], options?: GlobOptions) => boolean;
+//# sourceMappingURL=has-magic.d.ts.map