App Router: `next/script` stylesheets and `nonce` propagation incomplete

This issue was created by an agent analysing CI failures from the Next.js Deploy Suite (vinext main vs Next.js v16.2.6, 2026-05-22).

Problem

The next/script component does not load stylesheets associated with scripts, does not pass through nonce attributes, and does not implement bootstrap-script preinitialization (multiple bootstrap scripts expected; only one rendered).

Stylesheets associated with `next/script` not loaded; nonce missing; preinit bootstrap scripts incomplete

Estimated Impact

~3 test failures across the deploy suite.

Affected Test Suites

• test/e2e/app-dir/app/index.test.ts (3 failures)

Recommendation

1. Reproduce first in vinext's own test suite. Add a <Script> with an associated stylesheet and a CSP nonce, plus a fixture asserting multiple preinit bootstrap scripts. Confirm each fails.

2. Load associated stylesheets. When <Script> has linked stylesheets via the Next.js metadata convention, emit corresponding <link rel="stylesheet"> tags.

3. Propagate nonce. Add the request nonce to every emitted script/style tag.

4. Implement bootstrap preinit. Match the number of preinit bootstrap scripts Next.js emits for next/script.

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Part of #1328.