fix(clerk-js): backport fail-fast slow-origin load for Core 2

[nikosdouvlis]

Backports the fail-fast slow-origin load fix from #9065 to the release/core-2 line.

When Clerk's Frontend API is slow or unreachable during load, a cold Clerk.load() could hang for a long time. The /client request had no timeout, and on a 5xx or network error the recovery path burned the full retry budget before Clerk was marked loaded, so during an origin outage the app sat unresponsive instead of degrading and rendering.

What changed
The /client fetch and the load-recovery token mint are now bounded by a 7s timeout, and the timed-out /client request is aborted instead of being left in flight (via a new optional abortSignal threaded through Client.fetch down to the native fetch signal). On a slow or failed /client, recovery renders identity from the __session cookie, clears the session's token cache so the mint bypasses the cache, and keeps the cookie identity if the mint times out. After a degraded load, the client is re-fetched in the background without a time limit so a slow-but-healthy origin recovers full client data without a reload. Also adds a timeLimit utility to @clerk/shared/utils.

As-is backport
This matches main's current behavior, including the known gaps documented on #9065: the /environment request is not yet bounded, and the recovery mint stops waiting but isn't cancellable. Those are intentionally carried over so core-2 tracks main, and will be backported once they're addressed there.

Adapted to core-2
release/core-2 diverged from main about 7 months ago, so this is an adaptation rather than a cherry-pick. Core-2 already had createClientFromJwt and the tokenFreshness guard (backported in #9090), so only the initClient recovery body in load() was swapped; the abortSignal plumbing and the timeLimit util are net-new. No #clientUpdateGeneration guard exists on core-2 and none was added.

Verification
On the core-2 branch: timeLimit 6/6, clerk.test.ts 109/109 (including 7 new degraded-load tests), jwt-client.test.ts 3/3, fapiClient.test.ts 26 passing, and the clerk-js declarations typecheck is clean.

[changeset-bot]

🦋 Changeset detected

Latest commit: 7853518

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 22 packages

Name	Type
@clerk/clerk-js	Patch
@clerk/shared	Patch
@clerk/chrome-extension	Patch
@clerk/clerk-expo	Patch
@clerk/agent-toolkit	Patch
@clerk/astro	Patch
@clerk/backend	Patch
@clerk/elements	Patch
@clerk/expo-passkeys	Patch
@clerk/express	Patch
@clerk/fastify	Patch
@clerk/nextjs	Patch
@clerk/nuxt	Patch
@clerk/react-router	Patch
@clerk/clerk-react	Patch
@clerk/remix	Patch
@clerk/tanstack-react-start	Patch
@clerk/testing	Patch
@clerk/themes	Patch
@clerk/types	Patch
@clerk/vue	Patch
@clerk/localizations	Patch

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Project	Deployment	Actions	Updated (UTC)
clerk-js-sandbox	Ready	Preview, Comment	Jul 10, 2026 11:00am
swingset	Error		Jul 10, 2026 11:00am

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commit: 7853518