[hsliuustc0106]

Summary

Follow-up to #31 (slim PR gate). Stacked on #31's tip.

• PR gate stays one job: ubuntu-latest · Node 24 · DSH 0.2.0-rc.2 (required check). Cost tweaks only on test.yml: cancel-in-progress only off main, paths-ignore for docs/** / **/*.md on push only (not on pull_request, so a required check is never skipped on docs PRs), job timeout-minutes: 20, 5-minute timeouts on npm ci / DSH install, persist-credentials: false.
• New Compatibility workflow (.github/workflows/nightly.yml):
  • Daily cron 0 16 * * * (00:00 Asia/Shanghai): ubuntu·Node22·DSH 0.2.0-rc.2 + ubuntu·Node24·DSH 0.2.1-alpha.1
  • Weekly cron 0 17 * * 6 (Sun 01:00 Asia/Shanghai): windows-latest·Node24·DSH 0.2.0-rc.2
  • workflow_dispatch always runs daily + weekly legs
  • Skip schedule when main had no commits in the window (24h / 7d)
  • Job names prefixed compat · … so they never collide with the required check
  • Plugin suites (social + tree) included
  • No macOS in GHA — hs runs that locally
• Local Mac CI: ds-bot/scripts/local-ci.sh + npm run ci:local (same gate steps + tip SHA pass/fail)

vs #29

This PR supersedes the matrix / compat parts of #29 (Windows / Node22 / DSH alpha / macOS-as-GHA). Remaining #29 pieces that are not here (hs to decide whether to keep #29 open for them):

• composite action .github/actions/flybot-tests
• package job + check-pack.mjs + tests-ok aggregate
• coverage on the PR-gate job
• release.yml (tag → GitHub Release)
• CodeQL + Dependabot
• SHA-pinned actions / actionlint step
• broader test.yml rewrite (lint-before-test order, cancel-in-progress nuance already partially mirrored)

Cost (estimate)

Change	Approx. minutes saved
PR gate 4→1 (#31, included)	~30–45 min / PR
docs-only push skip	1 full Test run / docs push
cancel superseded PR runs	varies; avoids hanging runners
Windows weekly not daily	~5–6× ~15–20 min/week ≈ 75–120 min/week
No macOS GHA (local instead)	~15–25 min / would-be macOS run (and macOS is the expensive runner)
Skip nightly when main idle	~20–40 min / idle night (only the 5-min window check runs)

Verifier

• ran: python3 yaml.safe_load on both workflows; bash -n ds-bot/scripts/local-ci.sh; Codex review → PASS (1 round)
• not run: full npm test / live GHA (workflow + script only); actionlint not on the box

Test plan

• After merge of ci: slim Test matrix to ubuntu Node 24 + DSH 0.2.0-rc.2 #31 (or with this stack), confirm Test still reports exactly one job named via the matrix template for ubuntu/24/rc.2
• Dispatch Compatibility by hand; expect daily (2) + weekly (Windows) legs, no macOS
• On Mac: cd ds-bot && npm run ci:local → PASS with tip SHA
• Do not merge until tip is green / hs says so