skill: package supabase/agent-skills into dockyard

[JAORMX]

Package agent skills from supabase/agent-skills into the Dockyard registry.

Source

• Repo: https://github.com/supabase/agent-skills
• License: MIT
• Upstream HEAD (at survey time): 3e7fd16 (2026-04-19)
• Skill count upstream: 2
• Trust signal: Official Supabase; 1.9k stars

Candidate skills

• supabase
• supabase-postgres-best-practices

Acceptance criteria

• One spec.yaml per selected skill under skills/<name>/
• spec.ref pinned to an audited upstream commit SHA
• task validate-skill passes for each
• task scan-skill findings triaged
• Single PR grouping all Supabase skills (branch skills/supabase)

Part of the vendor-by-vendor sweep following #466 (Trail of Bits).