fix: generate types on dev server startup

[svelte-triage-bot]

Fixes #17032.

Synchronizes generated files and route types during Vite dev-server initialization, before any request is received. Parameter matcher validation remains deferred because it requires the initialized Vite SSR runner.

Adds a regression test that starts a real Vite development server without making a request and verifies route types already exist.

Tests:

• pnpm -F @sveltejs/kit test:unit
• pnpm -F @sveltejs/kit check
• pnpm -F @sveltejs/kit prepublishOnly
• pnpm lint
• pnpm format

[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from cf76b3c:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/cf76b3c0b8f61550d8f75e2d7bed9225cb1a5aa0

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/17034

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: cf76b3c

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

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[teemingc]

@svelte-triage-bot investigate the failing CI job

[dummdidumm]

@svelte-triage-bot you failed at the above request, investigate why through your feedback tool

[svelte-triage-bot]

I’m analyzing the failed workflow handling and recording the findings in the bot feedback tracker.

[dummdidumm]

@svelte-triage-bot you failed at the above request, investigate why through your feedback tool

[svelte-triage-bot]

I’ve started a feedback analysis of the failed CI-investigation handling.