docs(agents): document orientation-first mode in user-facing docs and code-review skill

Tracks WI-04 from the orientation-first review integration epic (#2090).

The orientation-first review mode introduced by Scenario D needs to be surfaced in user-facing documentation and the HVE getting-started guide so contributors know the loop exists and how to use it.

Acceptance criteria:

• The HVE guide references the orientation-first review mode and explains the Scenario D loop at a user-facing level.
• .github/skills/coding-standards/code-review/SKILL.md is updated to document the walkthrough-protocol and dispatch-loop as user-accessible entry points.
• Documentation does not require understanding the internal dispatch-manifest.json or diff-state.json contracts.

References:

• Parent epic: #2090
• Affected files: HVE getting-started docs, .github/skills/coding-standards/code-review/SKILL.md
  Related to #2090

Generated by Issue Triage for issue #2090 · 70.8 AIC · ⌖ 13.1 AIC · ⊞ 28.5K · ◷

Start with the HVE getting-started docs and .github/skills/coding-standards/code-review/SKILL.md. Document the orientation-first review mode and Scenario D loop for users, including the walkthrough-protocol and dispatch-loop as entry points. Done means both locations explain how to use the loop without requiring knowledge of dispatch-manifest.json or diff-state.json.