fix(style): read a trailing comment as a comment, not as a member

[Reefact]

Summary

A wrapped suppression closing with a trailing // comment was passed over in silence — in both modes, with exit 0. That is the one outcome indistinguishable from a clean tree, which is the failure this checker and its test exist to prevent.

Reproduced

class Wrapped {
    [SuppressMessage("Category", "RULE0011",
        Justification = "Wrapped, and closing with a comment after it.")] // a note
    void WrappedThenAComment() { }
}

$ tools/style/lint-layout.sh Wrapped.cs        →  Nothing to report.   exit 0
$ tools/style/lint-layout.sh --fix Wrapped.cs  →  Nothing to report.   exit 0

The checker asks two questions of the line the attribute closes on: does the attribute end here ()] anywhere), and does the line end here ()] at the end). The second answered no, because a comment followed — so the site was filed as the shape the checker admits it cannot read, a )] with a member after it, and produced no record at all. Not a report, not a decline: nothing. So --fix also had nothing to exit non-zero for.

A wrapped suppression could therefore escape the rule entirely by carrying a note.

Type of change

• Bug fix
• New feature
• Breaking change to the public API
• Refactoring
• Analyzer / diagnostic change
• Tests
• Documentation
• Build / CI / tooling

Changes

• closesLine also accepts )] followed by only a // comment. A // runs to the end of the line, so nothing can be hiding behind it and joining up to that line is safe. A /* is deliberately still unread — a member can follow its close on the same line, and telling that apart is parsing C# again.
• Two cases join the checker's own test: the wrapped-then-comment site it now rewrites, and a block-comment-then-member site it must still leave alone. Both counts the test asserts move with them (ten sites, ten lines removed).
• CLAUDE.md, CONTRIBUTING.md and docs/for-users/CONTRIBUTING.fr.md all enumerate the shapes the checker stays silent on. A trailing comment is now named as not one of them, since reading it as one is what cost the rule its teeth.

Scope

The repository carried no site of either shape — lint-layout.sh over the tree is still "Nothing to report." — so no C# changes with this.

No changelog entry: the checker is a repository tool, not something the packages ship, and the changelog documents the packages.

Testing

• tools/style/lint-layout.test.sh — passes; fails without the fix on the new case
• tools/style/lint-layout.sh over the tree — nothing to report
• dotnet test — documentation suite green (192), which is what the CONTRIBUTING translation pairing runs through
• tests/PackageSmokeTest/run.sh — not run: no packaging, analyzer or entry-point change; nothing under src/ is touched

Public API

• No change to the public surface
• The surface changed and the baseline was updated in the same commit

Documentation

• README / docs/ updated
• The French counterpart was updated to match
• CHANGELOG.md and docs/for-users/CHANGELOG.fr.md both updated
• No documentation change required

🤖 Generated with Claude Code

https://claude.ai/code/session_01M5U2BZXpHQr7YcfNHVx9dA

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