Skills: align SKILL.md frontmatter with the Agent Skills standard (require name + description; enforce name==dirname)

[wz-gsa]

Problem

Our schemas/skill.schema.json diverges from the Agent Skills open standard that Claude Code, OpenCode, Gemini CLI, Codex, Copilot, and Cursor all implement. The standard requires exactly two frontmatter fields for discovery:

• name — required, 1-64 chars, ^[a-z0-9]+(-[a-z0-9]+)*$, must equal the skill's directory name.
• description — required, 1-1024 chars; every agent uses it for progressive-disclosure discovery (loaded at startup to decide relevance).

OpenCode recognizes only name/description/license/compatibility/metadata and ignores unknown fields.

What our schema does today

• REQUIRES id/version/title/type/status/owners/primary_personas/requires/output/quality_gates with additionalProperties: false.
• Makes name optional — 17 of 27 skills under .agents/skills/ have no name: (verified). Strict consumers that key on name won't surface them, or will fall back to dirname unevenly.
• description is optional and capped at 300 chars (one skill already hits 312). The standard allows 1024; a weak/absent description degrades cross-model discovery.

Proposal (consensus 7/7 approved, higher_order)

1. For type: skill, make name + description required. Enforce the standard name regex and name == directory basename. Raise description max to 1024 with a meaningful minimum (>=20 chars, per AI/ML voter).
2. Keep the rich governance/routing fields (id, routing, risk_tier, …) as additive metadata the standard ignores. Decide explicitly: keep top-level (unknown-field-ignored) vs namespace under metadata: (spec-clean). Recommend top-level for now to avoid a mass rewrite; document the decision.
3. Backfill the 17 missing name: fields (= dirname) before flipping the schema to required, so CI doesn't hard-fail.
4. Add a validator check + pytest asserting name == id == dirname and standard-conformance across all skills.

Acceptance

• All 27 skills validate as Agent Skills skills (name+description conformant).
• New test enforces name==id==dirname.
• No regression in the router or INDEX generation.

Related: nested-directory conformance (separate issue), ship-patterns-as-kit (separate issue).

AI-assisted (OpenCode); consensus-reviewed. Requires human review.