What

README.md cites protobuf 3.21.12 while CLAUDE.md cites 4.25.1. Pick the authoritative version (vcpkg.json), update both docs, and add a CI check that prevents drift.

• Current: Two conflicting version claims in public-facing docs
• Expected: Single source of truth in vcpkg.json; both docs agree
• Scope: README.md, CLAUDE.md, .github/workflows/docs-verify.yml (new)

Why

• Consumers choosing a protobuf toolchain end up on the wrong version, breaking the build
• Documentation drift is a recurring issue flagged in DOC_REVIEW_REPORT.md:39

How

Technical Approach

1. Confirm pinned version in vcpkg.json
2. Update both docs to match
3. Add docs-verify.yml running a short grep to assert versions match vcpkg.json

Acceptance Criteria

• README.md and CLAUDE.md cite the same protobuf version as vcpkg.json
• CI fails if docs drift from vcpkg.json
• DOC_REVIEW_REPORT.md entry resolved