fix(members): hint at re-run init when legacy pre-0.25 roster is ignored

[Parithosh-Varma]

Fixes #735 (symptom-level: silent empty roster after 0.25 upgrade).

Problem

0.25 moved the member roster to the teamai-reports orphan branch. Teams upgrading with members/ still on the default branch get a bare No team members registered with no explanation, although their roster exists.

Fix

In listMembers, when the reports worktree yields zero members in branch-worktree mode and legacy members/*.yaml files exist in the clone, print an actionable warning naming the count, path, and recovery (teamai init re-registers each member on teamai-reports). Deliberately read-only: no new commands, no data-path changes, legacy files still ignored per existing tests.

Test plan

• npx tsc --noEmit: clean.
• npx vitest run on members/membership/single-repo-mode/git-kind-reports/reports-branch-readonly: 5 files, 92 tests pass (incl. 1 new: legacy hint).
• E2E with real built CLI (npm run build, isolated HOME, local bare remote, omitted-kind config = reporter's case):
  • legacy members/ present -> No team members registered + warn pointing at teamai init;
  • legacy members/ absent -> message only, no warn.
• Docs: no wording changes needed (no README/docs mention the message).

[jeff-r2026]

Thanks for your attention. This issue has been assigned.