Folder-as-resource: publish a skill (review → public flow)

[astsiapanay]

Parent

#1633 — DIAL Folder As Resource (EPIC)

What to build

Publish a skill as a whole through the existing review → public flow.

• The whole skill is the published unit. Publishing copies the entire tree through source → review → public.
• At each hop, re-synthesize a fresh, valid marker: correct target URL, fresh aggregate etag, and a fresh single version (currentVersion) pointing at the copied tree — never carry the source marker verbatim.
• Add SKILL to the set of publishable resource types so it flows through the existing publication controllers/services.

Acceptance criteria

• SKILL is registered as a publishable type and flows through the existing publication request/approval lifecycle.
• Publishing copies the whole tree source → review → public, re-synthesizing a valid marker (correct target URL, fresh etag, fresh version) at each hop.
• A published skill is readable at its public location and is structurally valid (marker + version present).
• Rejecting/withdrawing a publication behaves consistently with other resource types.
• Tests cover the full publish lifecycle and marker re-synthesis at each hop.

Blocked by

• Folder-as-resource foundation: SKILL type, v2 route, whole-resource PUT/GET #1634
• Folder-as-resource: access control integration for skills #1640