skill: package atlassian/forge-skills into dockyard

[JAORMX]

Package agent skills from atlassian/forge-skills into the Dockyard registry.

Source

• Repo: https://github.com/atlassian/forge-skills
• License: Apache-2.0
• Upstream HEAD (at survey time): 0d60ac5
• Skill count upstream: 3
• Trust signal: Official Atlassian; Anthropic skills launch partner

Candidate skills

Full curation at packaging time.

Acceptance criteria

• One spec.yaml per 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 Atlassian Forge skills (branch skills/atlassian)

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