fix(pull): include shared root CLAUDE.md fragments

[dvd233]

Summary

• Include shared claudemd/*.md files at the team-repo root in every eligible CLAUDE.md bundle.
• Keep namespace filtering unchanged for claudemd/<namespace>/*.md files.
• Add a regression assertion to the existing pull/skip-sync suite.

Fixes the root-level claudemd portion of #649.

Root cause

collectClaudemdFiles only iterated namespace directories. Root-level files were therefore invisible when a member had an active role, even though the pull contract treats root-level instructions as shared with everyone. Members without a role happened to receive them only because the unscoped fallback scanned all entries.

Validation

• Regression red on origin/main: the existing pull suite failed the new root-level instruction assertion.
• npx vitest run src/__tests__/pull-skip-sync.test.ts: 26 passed.
• npm run typecheck: passed.
• npm run build: passed.
• git diff --check: passed.
• Final open-PR audit: 9 open PRs; fix(pull): report actual sync outcome instead of team-repo item count #597 touches src/pull.ts but has no claudemd collector hunk, so no semantic competition.

[github-actions]

• [P1 blocking] Missing required real-CLI end-to-end verification. The Validation section lists Vitest, typecheck, build, and diff checks, but no actual teamai CLI run or result. Per the repository’s review rules, the PR description must include a concrete end-to-end/real-CLI test plan and verification record before merge.