Vendor exact Matt productivity and engineering skills snapshot

[huynhtandat223]

Summary

• Vendor the exact Matt Pocock skills snapshot under custom-skills/matt/.
• Preserve the existing .agents/skills/planner/matt/ bundle and all planner behavior.
• Include the upstream MIT license, provenance, and reproducible SHA-256 inventory.

Source

• Repository: https://github.com/mattpocock/skills
• Commit: 84fdeffd12f2ee307994d1eb6feb48173b6e0502
• Base: origin/main at 59c71c941b46f4e60e35de46076fd235c109ec09

Verification

• 76/76 source files and the upstream license match destination bytes.
• 77/77 inventory rows have equal source/destination SHA-256 hashes and byte counts.
• All copied SKILL.md frontmatter blocks are preserved.
• 62 source-resolvable relative links map to valid destination targets.
• git diff --check passes.
• Final diff against origin/main contains only custom-skills/matt/**.

Part 2 duplicate removal and planner reference changes are explicitly paused.
Do not merge PR #11; it remains audit-only.