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/minimatch/dist/commonjs/unescape.d.ts

@@ -0,0 +1,22 @@
+import type { MinimatchOptions } from './index.js';
+/**
+ * Un-escape a string that has been escaped with {@link escape}.
+ *
+ * If the {@link MinimatchOptions.windowsPathsNoEscape} option is used, then
+ * square-bracket escapes are removed, but not backslash escapes.
+ *
+ * For example, it will turn the string `'[*]'` into `*`, but it will not
+ * turn `'\\*'` into `'*'`, because `\` is a path separator in
+ * `windowsPathsNoEscape` mode.
+ *
+ * When `windowsPathsNoEscape` is not set, then both square-bracket escapes and
+ * backslash escapes are removed.
+ *
+ * Slashes (and backslashes in `windowsPathsNoEscape` mode) cannot be escaped
+ * or unescaped.
+ *
+ * When `magicalBraces` is not set, escapes of braces (`{` and `}`) will not be
+ * unescaped.
+ */
+export declare const unescape: (s: string, { windowsPathsNoEscape, magicalBraces, }?: Pick<MinimatchOptions, "windowsPathsNoEscape" | "magicalBraces">) => string;
+//# sourceMappingURL=unescape.d.ts.map