CLAUDE.md cites ci.yml for three toolchain commands the #553 split moved into reusable workflows

[drmoisan]

Summary

CLAUDE.md cites .github/workflows/ci.yml as the authority for three toolchain commands. PR #556
(#553, the CI parallel job split) moved those commands into reusable workflows, so the citations name
a file that no longer contains them.

Detail

Post-split, .github/workflows/ci.yml contains no msbuild or csharpier invocation at all. It is
a dispatcher of five uses: calls.

Stale references in CLAUDE.md:

• line ~194 — attributes the analyzer step's /t:Build /m to ci.yml; it now lives in
  .github/workflows/_build-analyzers.yml.
• line ~202 — attributes the CSharpier pinned-version invocation to ci.yml; it now lives in
  .github/workflows/_format-check.yml.
• line ~210-211 — states the nullable command is "character-for-character the command in
  .github/workflows/ci.yml (step 'Build with nullable warnings treated as errors')". ci.yml
  contains no step of that name; it is a job name in .github/workflows/_build-nullable.yml.

The claims themselves remain true of the tree; only the file being cited is wrong.

Why it matters

CLAUDE.md is always loaded into every agent session and is the top of the policy precedence order.
An agent that follows the citation to verify a command will not find it, and the third reference
names a step that does not exist anywhere under that name.

The corresponding text in .claude/rules/csharp.md was corrected during the main merge at
fb8eff9b; the same fix was not applied to CLAUDE.md.

Suggested resolution

Repoint the three references to _build-analyzers.yml, _format-check.yml, and _build-nullable.yml
respectively. Documentation-only; no logic change.

Found during the build-ci-coverage-gate-fidelity epic fan-in review.