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/fast-uri/benchmark/equal.mjs

@@ -0,0 +1,51 @@
+import { Bench } from 'tinybench'
+import { fastUri } from '../index.js'
+
+const {
+  equal: fastUriEqual,
+  parse: fastUriParse,
+} = fastUri
+
+const stringA = 'example://a/b/c/%7Bfoo%7D'
+const stringB = 'eXAMPLE://a/./b/../b/%63/%7bfoo%7d'
+
+const componentA = fastUriParse(stringA)
+const componentB = fastUriParse(stringB)
+
+const benchFastUri = new Bench({ name: 'fast-uri equal' })
+
+benchFastUri.add('equal string with string', function () {
+  fastUriEqual(stringA, stringA)
+})
+
+benchFastUri.add('equal component with component', function () {
+  fastUriEqual(componentA, componentA)
+})
+
+benchFastUri.add('equal component with string', function () {
+  fastUriEqual(componentA, stringA)
+})
+
+benchFastUri.add('equal string with component', function () {
+  fastUriEqual(stringA, componentA)
+})
+
+benchFastUri.add('not equal string with string', function () {
+  fastUriEqual(stringA, stringB)
+})
+
+benchFastUri.add('not equal component with component', function () {
+  fastUriEqual(componentA, componentB)
+})
+
+benchFastUri.add('not equal component with string', function () {
+  fastUriEqual(componentA, stringB)
+})
+
+benchFastUri.add('not equal string with component', function () {
+  fastUriEqual(stringA, componentB)
+})
+
+await benchFastUri.run()
+console.log(benchFastUri.name)
+console.table(benchFastUri.table())