D1: pure planner — profile selection ↔ showcase publish/unpublish (#178)

[xenodeve]

Parent

Part of #178

What to build

Pure planning helper: given a member GitHub identity, a member_projects URL/name, the new selected value, and candidate projects rows, return unpublish | republish | noop for at most one matching personal github-sourced showcase row. Match by GitHub owner/repo (case-insensitive) or normalized html URL. Never target owner_type=team. No DB I/O in this slice — unit tests only.

Acceptance criteria

• Deselect + matching personal published row → unpublish
• Select + matching personal non-published row → republish
• No matching row / team row / wrong member → noop
• Unit tests at the planner seam with known fixtures

Blocked by

None - can start immediately

[xenodeve]

EN

D1 done on feat/178-member-showcase-sync: planShowcaseSelectionSync + 7 unit tests green.

TH

D1 เสร็จบน branch แล้ว