QVAC-17994 feat[skiplog]: add sdk-backmerge skill

[opaninakuffo]

Note: be concise and prefer bullet points.

🎯 What problem does this PR solve?

• Releasing an SDK pod package requires two PRs per gitflow.md "Keep main aligned": one into release-<pkg>-<x.y.z>, and a follow-up backmerge into main carrying the version bump + changelog. The follow-up was a manual step, easy to forget.
• sdk-pr-create didn't know about release-branch targets, so the flow was: user runs the skill, gets the release PR, then has to remember to open the backmerge PR by hand (with the right cherry-pick base, the [skiplog] tag, the right title format, etc.).

📝 How does it solve it?

• New skill codifies backmerge PR creation end-to-end: pre-flight → resolve cherry-pick source → no-op detection (merge-tree simulation vs upstream/main^{tree}) → branch creation off upstream/main → cherry-pick (-x) → conflict triage with auto-resolve list (package.json version, aggregated CHANGELOG.md) → late-no-op re-verify → push → title/body assembly → gh pr create.
• Title guidance is validator-aware: chore[skiplog|notask]: backmerge … (single bracket, pipe-separated) is the tickless form per scripts/sdk/validator.cjs; chore[skiplog][notask]: is explicitly called out as rejected.
• Extends .cursor/skills/sdk-pr-create/SKILL.md with a "Release Target Dual-PR Flow" section: when the just-created PR's base is release-<pkg>-<x.y.z>, it auto-chains into sdk-backmerge so both PRs are opened in one run. Includes fail-stop policy on non-trivial cherry-pick conflicts and an --no-backmerge opt-out.

🧪 How was it tested?

• Exercised live on a TEST release branch (release-test-sdk-0.9.2 on tetherto/qvac). Both PRs were opened in a single chained sdk-pr-create → sdk-backmerge run, then closed once the flow was confirmed:
  • Release PR: chore[notask]: release sdk 0.9.2 #1770 — chore[notask]: release sdk 0.9.2 (head chore/sdk-0.9.2-release-prep → base release-test-sdk-0.9.2)
  • Backmerge PR: chore[skiplog|notask]: backmerge release-test-sdk-0.9.2 — version bump, changelog #1771 — chore[skiplog|notask]: backmerge release-test-sdk-0.9.2 — version bump, changelog (head backmerge/release-test-sdk-0.9.2 → base main)
• -x cherry-pick footer preserved on the backmerge commit afb2ab3 ("cherry picked from commit 74109c9").
• [skiplog|notask] title format accepted by scripts/sdk/validator.cjs.

comments

[opaninakuffo]

review

[github-actions]

Tier-based Approval Status

**PR Tier:** TIER1

**Current Status:** ✅ APPROVED

**Requirements:**
- 1 Team Member approval ✅ (1/1)
- 1 Team Lead OR Management approval ✅ (1/1)



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