fix: Reject all pending query promises when a query fails before resolving with a value for the first time

[elliott-with-the-longest-name-on-github]

Closes #16848

Failure Sequence

1. Query request A starts before the query has ever loaded successfully. #ready is false.
2. A refresh starts request B while A is still pending.
3. B fails.
4. The query marks B’s error, but resolves A’s internal promise because B superseded it.
5. A’s public promise waits for tick(), then returns #current.
6. Because no request has succeeded, #current is undefined.
7. The component receives undefined rather than a rejected promise, so <svelte:boundary> does not render its failure snippet. Accessing something like result.map(...) instead throws later.

The same problem occurs when fail() clears pending requests.

Fix

If we see that the internal promise has resolved but #ready has not yet been set, reject with #error (or a fallback, which shouldn't ever be reached).

[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from 61fb015:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/61fb0156addb8666a86a883cb226b2c8878d8385

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16890

[changeset-bot]

🦋 Changeset detected

Latest commit: 61fb015

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

This PR includes changesets to release 1 package

Name	Type
@sveltejs/kit	Patch

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-16890-svelte.vercel.app/