feat: render QA actors as skills for directory targets and document the consumption contract #344

Phase A work unit 4 of the maintainer-approved scoped plan (docs/design/issue-332-powershell-windows.md, Phase A revision v2).

Scope

• QA actors project as skills for directory targets: the lens actors are self-contained SKILL.md files (already proven by the TARS vendoring).
• No QA backend binding is added: a directory target does not run qa run backends; QA lifecycle rules are unchanged.
• Documentation: the Agent Skills specification (agentskills.io) is the consumption contract for directory-target output; document the mode, the flag, and its guarantees in the operating guide.

Acceptance criteria

• QA actors appear in a directory-target install with valid SKILL.md frontmatter (name, description, license, metadata).
• Docs describe the flag, guarantees, and consumption contract; help text updated wherever install options are documented.

Checks

• Structural conformance of projected actor files; docs review against the operating guide.

Refs #332