fix: quote argument-hint so Copilot CLI 1.0.65 loads SKILL.md

[thejesh23]

Bug

Copilot CLI 1.0.65 tightened SKILL.md frontmatter validation and now requires argument-hint to be a string. In YAML, an unquoted value that starts with [ is parsed as a sequence, so:

argument-hint: [senpai-name-or-slug]

parses as ["senpai-name-or-slug"] (a list) and Copilot CLI 1.0.65 rejects the skill at load time.

Fix

Wrap the value in double quotes so YAML parses it as a string. The rendered hint is unchanged.

- argument-hint: [senpai-name-or-slug]
+ argument-hint: "[senpai-name-or-slug]"

Only one file was affected in this repo: SKILL.md.

Compatibility

• Claude Code / older Copilot CLI: still valid — the quoted form has always been legal YAML and renders identically.
• Copilot CLI 1.0.65+: now loads the skill successfully.
• The same latent YAML issue exists on Claude Code and is tracked in anthropics/claude-code#22161.

Test plan

• python3 -c "import yaml; ..." on the updated frontmatter yields str (not list) for argument-hint.
• grep -rn "argument-hint:" shows no remaining unquoted [ values in the tree.
• Maintainer: install the skill under Copilot CLI 1.0.65 and confirm it loads without a frontmatter validation error.
• Maintainer: install under Claude Code and confirm /create-senpai still shows the [senpai-name-or-slug] argument hint as before.

[thejesh23]

Tracking issue: #4 — captures the bug diagnosis and reproducer separately for anyone searching the repo who lands there before this PR.