test(e2e): Add trace test for background use cache revalidation

[s1gr1d]

Add a test for background stale-while-revalidate refills of use cache entries. Target behavior: the refill is not stitched onto the serving trace. It should run in its own trace, links back to the request that triggered it, and becomes the cache_origin for future hits. Currently in a "failed" state (test.fail()) as this is not yet implemented. Production only — SWR timing does not hold on the dev server.

GET /api/use-cache-swr?id= — cacheLife({ stale: 5, revalidate: 2, expire: 300 }); sleep 3s after fill

T1 (fill)               T2 (stale hit)                T3 (hit)
|- put ck:A <-------------o get hit=true ck:A          |- get hit=true ck:A
|
TR: cache.revalidate  (own trace, NOT part of T2)            |
^- link back to T2 (link type TBD in the RFC)               |
|- put ck:A  <----------------------------------------------o cache_origin

Closes #24732
Linear https://linear.app/getsentry/issue/JS-3805/trace-test-for-background-use-cache-revalidation

[github-actions]

size-limit report 📦

⚠️ Warning: Base artifact is not the latest one, because the latest workflow run is not done yet. This may lead to incorrect results. Try to re-run all tests to get up to date results.

Path	Size	% Change	Change
@sentry/browser	29.24 kB	-	-
@sentry/browser - with treeshaking flags	27.5 kB	-	-
@sentry/browser - with treeshaking flags tracing without tracing	27.4 kB	-	-
@sentry/browser (incl. Tracing)	51.15 kB	-	-
@sentry/browser (incl. Tracing + Span Streaming)	51.17 kB	-	-
@sentry/browser (incl. Tracing, Profiling)	54.18 kB	-	-
@sentry/browser (incl. Tracing, Replay)	90.76 kB	-	-
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	79.86 kB	-	-
@sentry/browser (incl. Tracing, Replay with Canvas)	95.46 kB	-	-
@sentry/browser (incl. Tracing, Replay, Feedback)	108.41 kB	-	-
@sentry/browser (incl. Feedback)	46.76 kB	-	-
@sentry/browser (incl. sendFeedback)	34.3 kB	-	-
@sentry/browser (incl. FeedbackAsync)	39.41 kB	-	-
@sentry/browser (incl. Metrics)	30.25 kB	-	-
@sentry/browser (incl. Logs)	30.51 kB	-	-
@sentry/browser (incl. Metrics & Logs)	31.18 kB	-	-
@sentry/react	31 kB	-	-
@sentry/react (incl. Tracing)	53.45 kB	-	-
@sentry/vue	36.74 kB	-	-
@sentry/vue (incl. Tracing)	53.7 kB	-	-
@sentry/svelte	29.26 kB	-	-
CDN Bundle	30.93 kB	-	-
CDN Bundle (incl. Tracing)	51.69 kB	-	-
CDN Bundle (incl. Logs, Metrics)	33.2 kB	-	-
CDN Bundle (incl. Tracing, Logs, Metrics)	53.66 kB	-	-
CDN Bundle (incl. Replay, Logs, Metrics)	73.92 kB	-	-
CDN Bundle (incl. Tracing, Replay)	89.28 kB	-	-
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)	91.25 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback)	95.45 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)	97.42 kB	-	-
CDN Bundle - uncompressed	91.4 kB	-	-
CDN Bundle (incl. Tracing) - uncompressed	153.77 kB	-	-
CDN Bundle (incl. Logs, Metrics) - uncompressed	97.97 kB	-	-
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed	159.73 kB	-	-
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed	227.54 kB	-	-
CDN Bundle (incl. Tracing, Replay) - uncompressed	273.5 kB	-	-
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed	279.44 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	287.2 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed	293.13 kB	-	-
@sentry/nextjs (client)	55.77 kB	-	-
@sentry/sveltekit (client)	51.59 kB	-	-
@sentry/core/server	39.95 kB	-	-
@sentry/core/browser	13.63 kB	-	-
@sentry/node	133.9 kB	+0.01%	+6 B 🔺
@sentry/node/import (ESM hook with diagnostics-channel injection)	82.43 kB	-	-
@sentry/node - without tracing	90.45 kB	+0.02%	+12 B 🔺
@sentry/node - without channel injection	112.41 kB	+0.01%	+11 B 🔺
@sentry/aws-serverless	98.72 kB	+0.01%	+5 B 🔺
@sentry/cloudflare (withSentry) - minified	206.49 kB	-	-
@sentry/cloudflare (withSentry)	513.73 kB	-	-

View base workflow run

[chargome]

Bit hard to follow what this actually does, tests are also failing?

[chargome]

grafted?