fix: prevent site storybook tests from hanging after completion (#23936)

The vitest process hung after all 2132 story tests passed because
leftover refetchInterval polls kept the Node.js event loop alive.
Components that set per-query refetchInterval override the
QueryClient default, causing HTTP requests through vite's proxy
to localhost:3000 (no backend) that never resolve cleanly.

Three fixes:

- preview.tsx: disable all automatic refetching defaults and cancel
  in-flight queries on story unmount via useEffect cleanup
- storybook.tsx: save/restore the original window.WebSocket in the
  withWebSocket decorator, clear pending timers in close()
- vite.config.mts: add explicit testTimeout, hookTimeout, bail, and
  retry settings to the storybook vitest project

Also fix 5 story files that imported from @testing-library/react
instead of storybook/test.

Makefile

@@ -856,6 +856,7 @@ pre-push:
 	start=$$(date +%s)
 	logdir=$$(mktemp -d "$${TMPDIR:-/tmp}/coder-pre-push.XXXXXX")
 	echo "$(BOLD)pre-push$(RESET) ($$logdir)"
+	test -d site/node_modules/.cache/storybook || (cd site/ && pnpm exec node scripts/warmup-storybook-cache.mjs)
 	echo "test + build site:"
 	$(MAKE) --no-print-directory -j$(PARALLEL_JOBS) MAKE_TIMED=1 MAKE_LOGDIR=$$logdir \
 		test \