docs: complete CONTRIBUTORS.md with the version-board/label table (satisfies #1517 req #2)

[cliffhall]

Background

Surfaced during the Wave-1 smoke/audit of PR #1537 (docs: add CONTRIBUTORS.md issues-only policy, closes #1517). The committed CONTRIBUTORS.md does not satisfy requirement #2 of #1517 — the version-board / base-branch / label mapping and the "Label by version" convention are absent (0 mentions of board, label, v1.5, no table). The PR description claims it contains "a table mapping v2 / v1.5 / v1 to their boards, base branches, and labels" — so the PR body over-claims and checklist item #2 is only partially met.

Scope

Complete CONTRIBUTORS.md (on PR #1537's branch chore/1517-contributors-md, since that file lives there and #1537 is still open) by adding:

• A table mapping each active version to its project board, base branch, and version label:
  • main → v1 board (project 11) → label v1
  • v1.5/main → v1.5 board (frozen) → label v1.5
  • v2/main → v2 board (project 28) → label v2
• A short "Label by version" note mirroring AGENTS.md (new issues/PRs must carry the label matching the target board/branch).

Keep it consistent with AGENTS.md (single source of truth) — do not contradict the issue/board policy already documented there. Update the PR #1537 body to stop claiming the table exists until it does.

Acceptance

• CONTRIBUTORS.md contains the version→board/branch/label table and the label-by-version note, satisfying Add CONTRIBUTORS.md: issues-only policy (share prompts, not PRs) #1517 requirement Request logging #2.
• Links/anchors still resolve; content is consistent with AGENTS.md.

Refs: #1517, #1537, tracking #1579.

[cliffhall]

AGENTS.md audit — PR #1537 (commit 79ca8f05)

Verdict: PASS — the version-board/label table now satisfies #1517 requirement #2, and the @claude re-review is clean.

Docs-only change — no executable feature, no visual UI, and no coverage surface, so there is no functional smoke test, Playwright screenshot, or coverage run applicable (Markdown-only edit to CONTRIBUTORS.md). Verification was mechanical:

• ✅ Version table present & well-formed (CONTRIBUTORS.md:46–50) — maps v1 → main → board 11 → v1, v1.5 → v1.5/main → board 39 (frozen) → v1.5, v2 → v2/main → board 28 → v2, plus a "Label by version" note mirroring AGENTS.md.
• ✅ Anchor #what-makes-a-good-issue-or-prompt-submission resolves to the existing heading.
• ✅ Relative links ./AGENTS.md and the PR-template ../blob/v2/main/CONTRIBUTORS.md resolve.
• ✅ Consistent with AGENTS.md — no contradiction with the documented issue/board policy.
• ✅ PR docs: add CONTRIBUTORS.md issues-only policy (#1517) #1537 body corrected — no longer over-claims; now Closes #1517 + Closes #1595.

AGENTS.md compliance: Mantine / TypeScript / Coverage all N/A (documentation-only change — no code, JSX, CSS, or test surface).

Merge caveat (non-blocking, flagged by the re-review): git merge-base origin/v2/main HEAD returns nothing — this branch shares no common ancestor with v2/main (unrelated histories). The additive ## Contributing section merges cleanly, but the branch's AGENTS.md "Project Status" wording is stale vs. v2/main. Merge v2/main in and eyeball the merged AGENTS.md before landing so Project Status isn't reverted/duplicated.

No custom smoke-test script was needed (docs-only).

[cliffhall]

🔗 Implemented by PR #1537. Its code is already integrated into the Wave 1 rollup branch 1579-wave-1 (see rollup PR #1601 / verification #1600). #1537 currently targets v2/main and will auto-show as Merged once the rollup lands in v2/main. The Development panel doesn't link it now because the closing keyword is on a non-default base branch.

[cliffhall]

Consolidated into #1517. Its unique content — the concrete version→board/label table (project 11 / v1.5-frozen / project 28) and the "Label by version" note — has been folded into #1517's requirement #2. The CONTRIBUTORS.md work lands via #1604 → v2/main. Closing as a duplicate.