chore: declare e2e coverage variants in one place

[Nic-Polumeyv]

Adding an e2e coverage variant (a server config flag such as SVELTE_ASYNC or ROUTER_RESOLUTION) currently means a script per variant per mode in the test app's package.json, another in packages/kit/package.json, another at the root, a hand-written webServer.env in the app's playwright.config.js, and tests reading the raw env var; CI rows then name the root script. #14644 copied #13379's block for this and asked whether that was right; nothing decided it. Playwright can't express these as projects because webServer is config-level and every entry boots regardless of --project.

Each app now declares its variants once in configure() (packages/kit/test/utils.js): a name mapping to the server env it needs. KIT_E2E_VARIANT selects one per run, which sets webServer.env, suffixes the project names and is exported as variant for tests. CI rows carry variant as data next to project/shard and name the apps directly, so the root and kit script layers that only existed to fan variants out are gone. Coverage is unchanged: same tests, same 26 jobs, same triggers (--list per cell before/after is identical up to the project-name suffix). This is the plumbing for trimming the matrix afterwards: which cells run, and with which variant, becomes a row edit rather than a script added at three layers.

options-2's REGISTER_SERVICE_WORKER / NODE_ENV=custom DYNAMIC_PUBLIC_ENV runs are now the service-worker and dynamic-env variants.

[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from 1aa4828:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/1aa4828ab6efd6f5752dc8688a0d391899ae7e85

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16845

[changeset-bot]

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Latest commit: 1aa4828

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-16845-svelte.vercel.app/