Setup syn54x skills

Configure the repo so specs, plans and progress all live in GitHub Issues and the build skills can find them. Prompt-driven: explore, present, confirm, then write.

Only the SDD set needs this: to-tickets-plus, build-epic, implement-issue, review-pr, review-panel, sync-progress, close-epic. The rest of the pack (scaffold-python-project, scaffold-frontend-project, prepare-release-notes, adhd, eli5) works with no per-repo configuration.

The SDD set sits on mattpocock/skills: its setup owns the issue tracker choice and the base triage labels, and this skill adds what the build side needs on top. Step 0 checks that the user has done both. This skill never installs or configures the upstream pack; both are the user's to run.

0. The spine: mattpocock/skills

Check, then stop or continue. Never install or configure anything in this step.

Installed? Are to-spec, to-tickets, tdd, grill-with-docs and setup-matt-pocock-skills among your available skills, or present on disk (~/.agents/skills/<name>, .agents/skills/<name>, ~/.claude/skills/<name>, or the mattpocock-skills plugin)? Any one path counts.

If not, print this and stop: