[hooks] [code_assets] Library dartdoc comments

[dcharkes]

Add library dartdoc comments that detail the main entry points for browsing the documentation of both packages.

Bug:

• [hooks] [code_assets] Documentation #2324

[github-actions]

PR Health

API leaks ✔️

The following packages contain symbols visible in the public API, but not exported by the library. Export these symbols or remove them from your publicly visible API.

Package	Leaked API symbol	Leaking sources

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License Headers ✔️

// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
no missing headers

All source files should start with a license header.

Unrelated files missing license headers

Files
pkgs/objective_c/lib/src/ns_input_stream.dart

This check can be disabled by tagging the PR with skip-license-check.

[coveralls]

coverage: 81.229% (+0.001%) from 81.228%
when pulling 15fe85f on library-docs
into c76ea57 on main.

[goderbauer]

LGTM

[goderbauer]

Maybe:

Suggested change

	/// [CodeAsset] can be added to the [BuildOutputBuilder] a build hook as
	/// A [CodeAsset] can be added to the [BuildOutputBuilder] in a build hook as

[auto-submit]

autosubmit label was removed for dart-lang/native/2687, because - The status or check suite health / breaking / run breaking health check has failed. Please fix the issues identified (or deflake) before re-applying this label.

[dcharkes]

I believe the CI breakage is due to dart-lang/ecosystem#375, skipping check.