fix: preserve payload initialization with code splitting groups

[svelte-triage-bot]

• Recursive application groups can absorb startup’s static dependencies, evaluating payload-backed exports before init() sets the payload.
• Preserve the delayed initialization and stable runtime hashes introduced by #16324, and retain the manifest isolation from #16372.
• Reserve payload and Vite’s preload helper in a first, highest-priority bootstrap group with explicit size/share limits. Comparing live versions only would leave $app/env, paths, and public-env initialization broken.
• Scope the change to split client builds; cover SSR/client-only startup, unchanged and actual version changes, and recursively grouped dynamic public env.

Fixes #17382

[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from 62792f6:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/62792f61a7e6736e1f6ef7ac2f9b0a1e378d159c

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/17386

Note

This PR is from a fork. A maintainer must approve approve each commit before it can be built and installed.

[changeset-bot]

🦋 Changeset detected

Latest commit: 62792f6

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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